Kyocera Corporation

Shigenobu Nakamura

Takeshi Okamura

Masaki Terazono

Katsushi Sakaue

Takafumi Tsurumaru

Tomohiro Kawamoto

Ken Yamamoto

Satoru Kamitani

Kyoji Uchiyama

Shinsuke Takenishi

Takahiro Maruyama

Susumu Ono

Hiroyuki Masuyama

Katsuya Toyota

Kouihi Hayashi

Masahiro Inagaki

Koichi Nagasaki

Hirotaka Tsuyoshi

Hideki Uchimura

Nobuyuki Ito

Takeshi Kato

Tsuyoshi Setoguchi

Koki Ashida

Junya Shoji

There are provided a multi-layer piezoelectric element in which an increase of oxygen vacancies in an electric-field concentration part of piezoelectric layers is suppressed and a decrease of an amount of displacement is suppressed, as well as to provide a piezoelectric actuator, an injection device and a fuel injection system provided with the multi-layer piezoelectric element. A multi-layer piezoelectric element includes a stacked body composed of piezoelectric layers and internal electrode layers which are stacked on each other, and a resin which evolves OHwhen being heated. Accordingly, it is possible to obtain a multi-layer piezoelectric element in which an increase of oxygen vacancies in an electric-field concentration part of piezoelectric layers is suppressed and a decrease of an amount of displacement is suppressed.

Multi-layer piezoelectric element, and piezoelectric actuator, injection device, and fuel injection system provided with the same

A purpose is to obtain a frequency characteristic of a good sound pressure. To achieve the purpose, an acoustic generator according to an embodiment includes a piezoelectric element (exciter), a flat vibrating body, and a resin layer. The piezoelectric element vibrates when an electric signal is input. To the vibrating body, the piezoelectric element is attached. The vibrating body vibrates with the piezoelectric element due to the vibration of the piezoelectric element. The resin layer is arranged to cover surfaces of the piezoelectric element and the vibrating body to which the piezoelectric element is attached. The resin layer is integrated with the vibrating body and the piezoelectric element. Also, to the resin layer, irregularity is provided.

Acoustic generator, acoustic generation device, and electronic device

An object is to provide a preferable frequency characteristic of a sound pressure. For achieving the object, an acoustic generator according to an embodiment includes a piezoelectric element (exciter), a flat vibration plate, and a frame body. The piezoelectric element receives input of an electric signal and vibrates. The piezoelectric element is attached to the vibration plate, and the vibration plate vibrates together with the piezoelectric element with the vibration of the piezoelectric element. The frame body is provided on an outer circumferential portion of the vibration plate. Corners on an inner circumferential surface of the frame body include at least curved surfaces, and at least one of the corners has a shape different from the shape of the other corners.

An acoustic generator according to an embodiment includes a vibrating body and an exciter. The exciter is provided on the vibrating body, and vibrates by an input of an electrical signal. The exciter includes a protrusion or a recess on/in a surface of a side of the vibrating body.

Acoustic generator, acoustic generating device, and electronic device

An acoustic generator disclosed herein includes: an exciter which vibrates by an electric signal being input; and a film-shaped vibrating body to which the exciter is bonded via a bonding material and which vibrates together with the exciter by the vibration of the exciter, wherein the bonding material has a protruded part which protrudes from an outer edge of the exciter when the vibrating body is viewed in plane, at least a part of the protruded part has an undulating shape so as to be different from a shape of the outer edge of the exciter, and a part without the bonding material is provided between the exciter and the vibration body.

Acoustic generator, acoustic generation device, and electronic apparatus

An acoustic generator according to an embodiment at least includes an exciter, a vibrating plate, and a frame body. The exciter is caused to vibrate by an electrical signal. The exciter is mounted on the vibrating plate, and the vibrating plate is caused to vibrate together with the exciter by the vibration of the exciter. The frame body is provided on the outer peripheral portion of the vibrating plate. The frame body includes two frame members having different thicknesses or widths, and the two frame members nip the vibrating plate to support the vibrating plate.

An acoustic generator according to an embodiment at least includes an exciter, a vibrating plate, a frame body, and a resin material. The exciter is mounted on the vibrating plate, and the vibrating plate is caused to vibrate together with the exciter by the vibration of the exciter. The frame body is provided on an outer peripheral portion of the vibrating body. The resin material is disposed in a space formed with the surface of the vibrating plate on which the exciter is disposed and an inner peripheral surface of the frame body to integrate the vibrating body and the exciter. The resin material is provided also on at least part of a surface other than the inner peripheral surface of the frame body.

There are provided a multi-layer piezoelectric element which is capable of suppression of occurrence of an imperfect area, suffers from no development of leakage current even with moisture intrusion, has long-term freedom from variations in displacement and can achieve stable driving, as well as to provide a piezoelectric actuator, an injection device, and a fuel injection system provided with the multi-layer piezoelectric element. A multi-layer piezoelectric element includes a stacked body in which piezoelectric layers and internal electrodes acting as positive and negative internal electrodes are laminated; an inorganic coating attached to a side surface of the stacked body where ends of both the positive internal electrodes and the negative internal electrodes are exposed; and metal particles composed predominantly of a metal element contained in the internal electrodes, the metal particles dispersed in the inorganic coating.

Multi-layer piezoelectric element, and piezoelectric actuator, injection device, and fuel injection system provided with same

An acoustic generator includes a vibrating body. The acoustic generator includes a frame member attached by a bonding material to an external peripheral portion of the vibrating body. The acoustic generator has an exciter provided on the vibrating body inside of the frame member. In this case, the acoustic generator further includes an extended portion of the bonding material provided to be extended on the vibrating body inside of the frame from the frame member.

An acoustic generator according to an embodiment is provided with a vibration body, an exciter (piezoelectric vibration element), and a coating portion. The exciter is joined onto the vibration body through a joining portion. The coating portion is provided from the exciter to the vibration body. Furthermore, at least a part of an outer periphery of the joining portion is positioned inside of an outer periphery of the exciter, and a part of the coating portion is interposed between the vibration body and the exciter.

A multi-layer piezoelectric element includes a stacked body in which piezoelectric layers and internal electrode layers are alternately laminated and a stress relaxing layer is disposed at part of portions between the piezoelectric layers, and an external electrode that is bonded to a side face of the stacked body so as to make electrical connection with the internal electrode layers, the internal electrode layers being not exposed on the side face of the stacked body, but the stress relaxing layer being exposed on the side face of the stacked body.

Multi-layer piezoelectric element with stress relaxing, and injection device and fuel injection system using the same

An object is to flatten a frequency characteristic. For achieving the object, an acoustic generator according to an embodiment includes a piezoelectric element (exciter) and a film (film-like vibrating body). The piezoelectric element receives input of an electric signal and vibrates. The piezoelectric element is bonded to the film through a bonding material and the film vibrates together with the piezoelectric element with the vibration of the piezoelectric element. Furthermore, the acoustic generator in the embodiment has voids in the bonding material.

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, 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, multi-layer piezoelectric device, injection apparatus and fuel injection system

A multi-layer piezoelectric element includes a stacked body configured so that piezoelectric layers and internal electrode layers are alternately laminated, and an external electrode composed of a sintered material of both electrically conductive particles and a glass, the external electrode which is bonded to a side surface of the stacked body and makes electrical connection with the internal electrode layers. The external electrode has a stacked body-side layer region containing glass as secondary constituent at its stacked body-facing side, and an exterior-side layer region containing glass as minor constituent at its exterior side. The glass of the exterior-side layer region is distributed along grain boundary of the conductive particles on an outermost surface of the exterior-side layer region.

Multi-layer piezoelectric element, and injection device and fuel injection system incorporating the multi-layer piezoelectric element

A piezoelectric actuator includes a stacked body composed of internal electrodes and piezoelectric layers which are stacked on each other; and a surface electrode disposed on at least one of main surfaces of the stacked body so as to be electrically connected to the internal electrodes. The internal electrodes each includes a first electrode and a second electrode. The stacked body has an active section in which the first electrodes and the second electrodes of the internal electrodes are arranged so as to overlap each other in a stacking direction thereof, and an inactive section which is every section of the stacked body other than the active section. An internal electrode placed on a one-main-surface side of the internal electrodes is configured so that its end part situated near a boundary between the active section and the inactive section is curved toward the other main surface.

Growing community of inventors

Kirishima, Japan

Shigenobu Nakamura