Ngk Insulators, Inc.

Kenkichi Nagai

Masahiro Kida

Kenshin Kitoh

Takahiro Tomita

Shigeharu Hashimoto

Hiroharu Kobayashi

Yoshiho Tomita

A ceramic material has a characteristic length Lof a micro-structure thereof that satisfies 0.1 L&#x2266;L&#x2266;100 L, and has thermal conductivity that monotonously increases from room temperature to 100&#xb0; C., where Ldenotes apparent mean free path of phonons at room temperature, and is defined as L=(3&#xd7;thermal conductivity)/(heat capacity&#xd7;speed of sound). The characteristic length Lof the micro-structure is an interval between particles of different type of material when the ceramic material includes a composite material in which the different type of material is dispersed in a base material, is an interval between one pore and another pore when the ceramic material includes a porous body, and is the crystalline particle size (interval between one grain boundary and another grain boundary) when the ceramic material includes a polycrystalline body.

Ceramic material and thermal switch

The heater includes a heater main body, a housing storing the heater main body therein, and a coating material arranged in at least a part between the heater main body and the housing and covering at least a part of the heater main body. The coating material is a material containing at least one of ceramic and glass, the heater main body has a cylindrical honeycomb structural portion having partition walls separating and forming a plurality of cells and a pair of electrode portions disposed on a side face of the honeycomb structural portion, the housing contains the heater main body so as to cover the side face side of the heater main body, and the partition walls of the honeycomb structural portion is of a material containing ceramic as the main component and produces heat by energization.

Heater

There is disclosed a heater which does not excessively heat a lubricating fluid but can rapidly raise a temperature of the lubricating fluid, even when a size thereof is small. A heater includes a honeycomb structure section including partition walls which contain a ceramic as a main component and generate heat by electrical conduction, and a plurality of cells which are partitioned and formed by the partition walls and extend through the honeycomb structure section from one end to another end to become through channels of a lubricating fluid; and a pair of electrodes which become an anode and a cathode to come in contact with the honeycomb structure section, thereby conducting the electricity through the partition walls of the honeycomb structure section.

Growing community of inventors

Nagoya, Japan

Kenkichi Nagai