Piezoelectric/electrostrictive device having increased strength

• US 6,404,109 B1
• Filed: 04/06/2000
• Issued: 06/11/2002
• Est. Priority Date: 10/01/1999
• Status: Expired due to Fees

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Kimura, Koji, Takeuchi, Yukihisa, Nanataki, Tsutomu
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): Zarroli, Michael C.
• Application Number:
  US09/544,013
• Time in Patent Office: 796 Days
• Field of Search: 310/321, 310/328, 310/330, 310/331, 310/324, 310/367, 310/368
• US Class Current: 310/348
• CPC Class Codes: H10N 30/01 Manufacture or treatment
• CPC Class Codes: H10N 30/05 Manufacture of multilayered piezoelectric or electrostrictive devices, or parts thereof, e.g. by stacking piezoelectric bodies and electrodes
• CPC Class Codes: H10N 30/053 by integrally sintering piezoelectric or electrostrictive bodies and electrodes
• CPC Class Codes: H10N 30/074 by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
• CPC Class Codes: H10N 30/2043 connected at their free ends, e.g. parallelogram type
• CPC Class Codes: H10N 30/501 with non-rectangular cross-section in stacking direction, e.g. polygonal, trapezoidal

Abstract

A piezoelectric/electrostrictive device including a pair of mutually opposing thin plate sections, a movable section, and a fixation section for supporting the thin plate sections and the movable section. At least one piezoelectric/electrostrictive element is arranged on the pair of thin plate sections, and a hole is formed by both inner walls of the pair of thin plate sections, an inner wall of the movable section, and an inner wall of the fixation section. The pair of thin plate sections are previously bent in directions to make mutual separation so that they have an outwardly convex configuration.

Claims

1. A piezoelectric/electrostrictive device comprising:

a pair of mutually opposing thin plate sections, a movable section, and a fixation section for supporting said thin plate sections and said movable section;

at least one piezoelectric/electrostrictive element arranged on at least one thin plate section of said pair of thin plate sections; and

a hole formed by both inner walls of said pair of thin plate sections, an inner wall of said movable section, and an inner wall of said fixation section, wherein;

at least a part of at least one of said thin plate sections is bent outwardly from the other thin plate section when said piezoelectric/electrostrictive element is in an inactivated state.

3. The piezoelectric/electrostrictive device according to claim 1, wherein 0<

δ

≦

0.15L is satisfied provided that a bent amount of said thin plate section is δ

, and a length of said thin plate section (distance between said inner walls of said movable section and said fixation section) is L.

4. The piezoelectric/electrostrictive device according to claim 1, wherein said thin plate section, said movable section, and said fixation section are composed of a ceramic substrate integrated into one unit by co-firing a ceramic green laminate and cutting off unnecessary portions.

5. The piezoelectric/electrostrictive device according to claim 4, wherein said piezoelectric/electrostrictive element has a film-shaped configuration including a pair of electrodes and a piezoelectric/electrostrictive layer, wherein at least one of said electrodes and said piezoelectric/electrostrictive layer is integrated with said ceramic substrate by means of sintering.

6. The piezoelectric/electrostrictive device according to claim 1, wherein said piezoelectric/electrostrictive element has a piezoelectric/electrostrictive layer and a pair of electrodes formed on said piezoelectric/electrostrictive layer.

2. A piezoelectric/electrostrictive device comprising:

a pair of mutually opposing thin plate sections, a movable section, and a fixation section for supporting said thin plate sections and said movable section;

at least one piezoelectric/electrostrictive element arranged on at least one of said thin plate sections; and

a hole formed by both inner walls of said pair of thin plate sections, an inner wall of said movable section, and an inner wall of said fixation section, wherein;

at least parts of said pair of thin plate sections are bent outwardly from each other when said piezoelectric/electrostrictive element is in an inactivated state.

7. A piezoelectric/electrostrictive device comprising:

a pair of mutually opposing thin plate sections, a movable section, and a fixation section for supporting said thin plate sections and said movable section;

at least one piezoelectric/electrostrictive element arranged on at least one thin plate section of said pair of thin plate sections; and

a hole formed by both inner walls of said pair of thin plate sections, an inner wall of said movable section, and an inner wall of said fixation section, wherein;

at least a part of each thin plate section is bent outwardly in a convex configuration from the other thin plate section when said piezoelectric/electrostrictive element is in an inactivated state.

8. A piezoelectric/electrostrictive device comprising:

a pair of mutually opposing thin plate sections, a movable section, and a fixation section for supporting said thin plate sections and said movable section;

at least one piezoelectric/electrostrictive element arranged on at least one thin plate section of said pair of thin plate sections; and

a hole formed by both inner walls of said pair of thin plate sections, an inner wall of said movable section, and an inner wall of said fixation section, wherein;

at least a part of at least one of said thin plate sections is bent outwardly from the other thin plate section when said piezoelectric/electrostrictive element is in an inactivated state; and

0<

δ

≦

0.15L is satisfied provided that a bent amount of said thin plate section is δ

, and a length of said thin plate section, which corresponds to a distance between said inner walls of said movable section and said fixation section, is L.

9. A piezoelectric/electrostrictive device comprising:

a pair of mutually opposing thin plate sections, a movable section, and a fixation section for supporting said thin plate sections and said movable section;

at least one piezoelectric/electrostrictive element arranged on at least one thin plate section of said pair of thin plate sections, said piezoelectric/electrostrictive element comprising a piezoelectric/electrostrictive layer and a pair of electrodes formed on both sides of said piezoelectric/electrostrictive layer, one electrode of said pair of electrodes being formed on at least said thin plate section; and

a hole formed by both inner walls of said pair of thin plate sections, an inner wall of said movable section, and an inner wall of said fixation section, wherein;

at least a part of at least one of said thin plate sections is bent outwardly from the other thin plate section when said piezoelectric/electrostrictive element is in an inactivated state.

10. The piezoelectric/electrostrictive device according to claim 9, wherein said piezoelectric/electrostrictive element is constructed in a stacked form comprising a plurality of units each including said piezoelectric/electrostrictive layer and said pair of electrodes.

11. A piezoelectric/electrostrictive device comprising:

a pair of mutually opposing thin plate sections, a movable section, and a fixation section for supporting said thin plate sections and said movable section;

at least one piezoelectric/electrostrictive element arranged on at least one thin plate section of said pair of thin plate sections;

a hole formed by both inner walls of said pair of thin plate sections, an inner wall of said movable section, and an inner wall of said fixation section; and

a gel material filling said hole, wherein;

at least a part of at least one of said thin plate sections is bent outwardly from the other thin plate section when said piezoelectric/electrostrictive element is in an inactivated state.