Kyocera Corporation

Takafumi Tsurumaru

Shigenobu Nakamura

Takeshi Okamura

Masaki Terazono

Ken Yamamoto

Tomohiro Kawamoto

Nobuyuki Ito

Tsuyoshi Setoguchi

A multilayer piezoelectric element includes a plurality of piezoelectric layers and a plurality of metal layers stacked alternately. The plurality of metal layers include a plurality of low-filled metal layers having a lower filling rate of metal composing the metal layers than oppositely disposed metal layers adjacent to each other in a stacking direction. The plurality of metal layers may include a plurality of thin metal layers having a smaller thickness than oppositely disposed metal layers adjacent to each other in a stacking direction. Where the plurality of metal layers are composed mainly of an alloy, the plurality of metal layers may include a plurality of high-ratio metal layers having a higher ratio of a component constituting the alloy than oppositely disposed metal layers adjacent to each other in a stacking direction.

Multilayer piezoelectric element and injector using the same

In a multilayer piezoelectric element in which a plurality of piezoelectric layers and a plurality of metal layers are stacked alternately, the plurality of metal layers include a plurality of low-filled metal layers having a lower filling rate of metal composing the metal layers than oppositely disposed metal layers adjacent to each other in a stacking direction. In a multilayer piezoelectric element in which a plurality of piezoelectric layers and a plurality of metal layers are stacked alternately, the plurality of metal layers include a plurality of thin metal layers having a smaller thickness than oppositely disposed metal layers adjacent to each other in a stacking direction. In a multilayer piezoelectric element in which a plurality of piezoelectric layers and a plurality of metal layers composed mainly of an alloy are stacked alternately, the plurality of metal layers include a plurality of high-ratio metal layers having a higher ratio of a component constituting the alloy than oppositely disposed metal layers adjacent to each other in a stacking direction.

In a multilayer piezoelectric element comprising a plurality of piezoelectric layers and a plurality of metal layers which are alternately stacked one upon another, the metal layers includes a plurality of high resistance metal layers having a higher electrical resistance than adjacent metal layers on the both sides. The high resistance metal layers are regularly arranged so as to interpose a plurality of different metal layers other than the high resistance metal layers. In another multilayer piezoelectric element in which a plurality of piezoelectric layers and a plurality of metal layers are alternately stacked one upon another, at least one layer of the metal layers is formed by a plurality of partial metal layers disposed between the piezoelectric layers.

A ceramic member in which the metal layers with high void ratio are sufficiently sintered to lower a residue of resin is produced. The method for manufacturing a ceramic member which comprises a step of forming a stacked compact from a plurality of metallic paste layers containing a metal component Mthat are stacked one on another via ceramic green sheets, and a step of firing the stacked compact, wherein at least one of plural metallic paste layers is formed as a second metallic paste layer that has the mass percentage X higher than that of the metallic paste layer that adjoin therewith in the stacking direction and a ceramic powder is contained in the second metallic paste layer in the step of forming the stacked compact, the mass percentage X being the proportion of the metal component Mto the total metal content in the metallic paste layer.

Method for manufacturing ceramic member, and ceramic member, gas sensor device, fuel cell device, filter device, multi-layer piezoelectric device, injection apparatus and fuel injection system

The multi-layer piezoelectric element comprises a stack having an active portion constituted from at least one piezoelectric layer and a plurality of internal electrodes consisting of first and second internal electrodes placed one on another, the active portion being subjected to expansion and contraction in response to a voltage applied across the first internal electrode and the second internal electrode, and external electrodes formed on two side faces of the stack with one thereof being connected to the first internal electrode and the other connected to the second internal electrode, wherein each of the external electrodes is constituted from three or more layers including a first layer formed in contact with the side face of the stack and a second layer formed on the first layer, to provide a multi-layer piezoelectric element having high durability.

Growing community of inventors

Kirishima, Japan

Takafumi Tsurumaru