Tdk Corporation

Nifco Inc.

Kinugawa Rubber Industrial Co., Ltd.

Aichi Kikai Kogyo Kabushiki Kaisha

Kinugawa Gomu Kogyo Kabushiki Kaisha

Shoji Inoue

Takashi Ito

Katsushi Yasuhara

Masahiko Watanabe

Atsuhito Matsukawa

Osamu Takeda

Kazuhiro Asaba

Yuji Nagahashi

Manganese-zinc base ferrite

The invention aims to provide a manganese-zinc ferrite exhibiting a high initial permeability over a broad band and especially in a low-frequency region of about 10 kHz and a method for preparing the same. A method for preparing a manganese-zinc ferrite by firing is characterized in that the firing includes a main temperature holding step at 1,200-1,450&deg; C. and a thermal ramp-down step prior to the main temperature holding step, and the lowest temperature reached by the mid-firing thermal ramp-down step is set in the range of 1,000-1,400&deg; C. and lower by at least 50&deg; C. than the hold temperature of the main holding step, thereby obtaining a manganese-zinc ferrite comprising 50-56 mol % calculated as Fe O of iron oxide, 22-39 mol % calculated as MnO of manganese oxide, and 8-25 mol % calculated as ZnO of zinc oxide as main components, and having a mean crystal grain size of more than 50 &mgr;m to 150 &mgr;m.

Manganese-zinc ferrite and making method

The Mn&mdash;Zn system ferrite according to the present invention contains main components comprising manganese oxide, zinc oxide and iron oxide, and subordinate components comprising bismuth oxide and molybdenum oxide. It comprises 22.0 to 25.0 mol % c of manganese oxide calculated as MnO, 22.0 to 25.0 mol% of zinc oxide calculated as ZnO and the remainder calculated as Fe,O,in main components. It has been sintered after adding thereto 50 to 400 ppm of a bismuth oxide component calculated as Bi,O,and 50 to 400 ppm of a molybdenum oxide component calculated as MoO,as subordinate component source materials. An initial magnetic permeability at 10 KHz is 8,500 or more at &minus;20 to 20&deg; C. and 10,000 or more at 20 to 100&deg; C., and the temperature characteristics of magnetic permeability is excellent.

Mn-Zn system ferrite

Ferrite and ferrite core for power supply

A ferrite core for line filters according to the invention comprises, as main components, manganese oxide in an amount of 13.5 to 16% by weight, calculated as MnO and zinc oxide in an amount of 14 to 16% by weight calculated as ZnO with the rest being iron oxide, and as subordinate components, silicon oxide in an amount of 50 to 200 ppm calculated as SiO.sub.2, calcium oxide in an amount of 100 to 350 ppm calculated as CaO, niobium oxide in an amount of 30 to 150 ppm calculated as Nb.sub.2 O.sub.5, molybdenum oxide in an amount of 20 to 300 ppm calculated as MoO.sub.3, and bismuth oxide in an amount of 100 to 800 ppm calculated as Bi.sub.2 O.sub.3. Such a core has high inductance at about 1 kHz and high impedance at about 500 kHz, and shows a high noise reduction coefficient over a wide frequency band.

Ferrite core for line filters

Manganese-zinc system ferrite

In a fastener for securing a weather strip to an automotive body panel provided with a cap portion for retaining the weather strip, a stem portion extending from the cap portion and adapted to be fitted into a through hole provided in the body panel, a radial flange provided in the stem portion adjacent the cap portion for abutting the outer surface of the body panel, and a plurality of engagement claws projecting radially from the stem portion for securing the stem portion in the through hole of the body panel, to reduce the force required for securing the fastener and facilitate the use of the fastener without compromising the fastening capability of the fastener, the stem portion has a substantially hollow cross section, and is provided with four axial slits at 90 degree interval. Thus, the separated parts of the stem portion are given with a sufficient yieldability without being affected by the rigidity of the radial flange, and the work of mounting the fastener is facilitated.

Fastener having axial slits and axially displaced engagement claws

A strip of molding which is installed on the side edge of windshield glass, being insertingly mounted on one end of a strip of channel having a U-shaped cross section, and being able to be installed together with a strip of drip seal, permitting to reduce installation time and create a neat appearance. A connective portion which comes in contact with the drip seal can be provided in the cross section of the windshield molding so that any abnormal sounds will be eliminated.

Windshield molding installation arrangement

Growing community of inventors

Chiba, Japan

Shoji Inoue