Hitachi Metals, Ltd.

Hitachi Cable, Inc.

Proterial, Ltd.

Hitach Cable, Ltd.

Masafumi Kaga

Tamotsu Kibe

Akinari Nakayama

Sohei Kodama

Takahiro Sugiyama

Haruyuki Watanabe

Motoharu Kajiyama

Hiroshi Ishikawa

Makoto Iwasaki

Yoshiaki Nakamura

Koki Hirano

Seiichi Kashimura

Izumi Fukasaku

Hidenori Yonezawa

Akihiro Tanba

Satoshi Yamamoto

An insulated electric wire is composed of a conductor, and a covering layer disposed around an outer circumference of the conductor. The covering layer has a plurality of flame retardant layers composed of a flame retardant resin composition, and an insulating layer interposed between the plurality of flame retardant layers. The insulating layer is made of a resin composition including a resin component, and the resin component includes 40% by mass or more of a resin having a melting point of 125 degrees C. or higher of 100% by mass of the resin component.

Insulated electric wire

An insulated wire includes a conductor, and a flame-retardant insulation layer that includes a resin composition including a flame retardant and is arranged around the conductor, and a water-blocking layer that is arranged around the flame-retardant insulation layer and has a water absorption of not more than 0.5% at saturation. The thickness of the water-blocking layer is not less than 25 &#x3bc;m.

Insulated wire

An insulated wire having an electrical wire structure capable of reducing an outer diameter while an insulation property and a flame-retardant property are highly kept is provided. In the insulated wire including: a conductor; and a coating layer arranged on an outer periphery of the conductor, the coating layer includes: a semiconductive layer having a volume resistivity defined by JIS C2151 that is equal to or smaller than 1.0&#xd7;10(&#x3a9;cm); an insulating layer arranged on an outer periphery of the semiconductive layer, the insulating layer having a volume resistivity defined by JIS C2151 that is larger than 5.0&#xd7;10(&#x3a9;cm); and a flame-retardant semiconductive layer arranged on an outer periphery of the insulating layer, the flame-retardant semiconductive layer having a volume resistivity defined by JIS C2151 that is equal to or smaller than 1.5&#xd7;10(&#x3a9;cm) and having an oxygen index defined by JIS K7201-2 that is larger than 40.

An insulated wire having an electrical wire structure capable of reducing a diameter while a direct-current stability property and a flame-retardant property are highly kept is provided. In the insulated wire including: a conductor; a flame-retardant semiconductive layer arranged on an outer periphery of the conductor; an insulating layer arranged on an outer periphery of the flame-retardant semiconductive layer; and a flame-retardant layer arranged on an outer periphery of the insulating layer, an oxygen index of the flame-retardant semiconductive layer defined by JIS K7201-2 is larger than 40, and a volume resistivity of the flame-retardant semiconductive layer defined by JIS C2151 is equal to or smaller than 5.0&#xd7;10(&#x3a9;cm).

An insulated wire having an electrical wire structure capable of reducing an outer diameter while an insulating property and a flame-retardant property are highly kept is provided. In the insulated wire including: a conductor; and a coating layer arranged on an outer periphery of the conductor, the insulated wire has a flame-retardant property that allows the insulated wire to pass a vertical tray flame test (VTFT) on the basis of EN 50266-2-4, has a direct-current stability that allows the insulated wire to pass a direct-current stability test in conformity to EN 50305.6.7, has a diameter of the conductor that is equal to or smaller than 1.25 mm, and has a thickness of the coating layer that is smaller than 0.6 mm.

An insulated wire, having an electrical wire structure capable of reducing an outer diameter while maintaining an insulating property and a flame-retardant property, includes a conductor and a coating layer arranged on an outer periphery of the conductor. The coating layer includes a plurality of flame-retardant layers, each made of a flame-retardant resin composition, and an insulating layer interposed between the plurality of flame-retardant layers. A ratio of a thickness of the insulating layer to a thickness of the coating layer is equal to or larger than 10% and equal to or smaller than 35%.

An insulated wire includes a conductor, a flame-retardant inner layer that is provided around the conductor and includes a metal hydroxide, and a water ingress prevention layer provided around the flame-retardant inner layer. The insulated wire may further include a flame-retardant outer layer provided around the water ingress prevention layer.

Insulated wire and cable

A differential signal cable is composed of two inner conductors, an insulator, which covers the two inner conductors separately or together, and an outer conductor, which covers a circumference of the insulator. When measured in a cable length of 1 m, an effective capacitance difference &#x394;X represented by Formula (1) below is not greater than 0.2 percent of an average value C of capacitances of the two inner conductors,&#x394;&#x2003;&#x2003;(1),where &#x394;C is a difference in capacitance between the two inner conductors, &#x394;L is a difference in inductance between the two inner conductors, and Zis a reference impedance (50 ohms).

Differential signal cable and production method therefor

A differential signal transmission cable includes a pair of differential signal lines arranged in parallel to each other, an insulation for bundle-covering the pair of differential signal lines, and a shield conductor wound around an outer periphery of the insulation. The insulation is configured such that an outer circumference thereof in a cross section perpendicular to a longitudinal direction thereof has an oval shape formed with a continuous convex arc-curve. The outer circumference of the insulation includes a first curved portion with a pair of symmetrical elliptical arcs located at both ends in a first direction along the arrangement direction of the pair of differential signal lines and a second curved portion with a pair of symmetrical elliptical arcs located at both ends in a second direction orthogonal to the first direction.

Differential signal transmission cable

A differential signal transmission cable includes two core wires, and a foamed insulation that collectively covers the two core wires by foaming extrusion molding. The foamed insulation is not more than 5% in a dispersion of foaming degree defined below in a cut surface when the cable is cut orthogonally to a longitudinal direction of the cable. In the cut surface, five regions are determined according to a predetermined procedures and a foaming degree (%) of the respective regions is measured. The dispersion of the foaming degree is defined by a difference between a foaming degree (%) in the region with a maximum foaming degree and a foaming degree (%) in the region with a minimum foaming degree.

Differential signal transmission cable and method of making same

A differential transmission cable includes at least one pair of inner conductors arranged in parallel and extending parallel to each other, and a foamed insulating material formed on the inner conductors by a collective extrusion coating and molding of a resin material by using a chemical foaming method and have a variation of foaming degree of not more than 1%. The variation of foaming degree is defined as a difference between a maximum value and a minimum value among foaming degrees (%) of the foamed insulating material at 20 positions at intervals of 50 cm in a longitudinal direction in an arbitrary part of 10 m cut out from the differential transmission cable.

Differential transmission cable and method of manufacturing the same

A parallel foamed coaxial cable includes one or more pairs of inner conductors aligned in parallel, a foamed insulation covering together the inner conductors and having a cross sectional shape including an elliptical shape, a rounded-rectangular shape or a quasi-elliptical shape formed by combining a plurality of curved lines, a non-foamed skin layer covering the foamed insulation and having a maximum thickness in a major axis direction of the cross sectional shape of the foamed insulation and a minimum thickness in a minor axis direction of the cross sectional shape of the foamed insulation, an outer conductor covering the non-foamed skin layer, and an insulation jacket covering the outer conductor. The maximum thickness of the non-foamed skin layer is not less than 1% of a major axis of the cross sectional shape of the foamed insulation.

Parallel foamed coaxial cable

A differential signal transmission cable includes a pair of differential signal lines arranged in parallel to each other, an insulation for bundle-covering the pair of differential signal lines, and a shield conductor wound around an outer periphery of the insulation. The insulation is configured such that an outer circumference thereof in a cross section perpendicular to a longitudinal direction thereof has an oval shape formed with a continuous convex arc-curve. The oval shape has a width in a first direction along the arrangement direction of the pair of differential signal lines being larger than a width in a second direction orthogonal to the first direction.

An insert molding method includes holding a plurality of insert members in a molding die to be separated from one another, and subsequently filling a resin into the molding die to fill a gap between the insert members and a periphery thereof with the resin to form an insert molded product such that the insert members are separated at a preset interval from one another. The molding die includes a space-maintaining projection for maintaining a separation interval between the insert members at the preset interval or more, the projection being formed on an inner wall surface of the molding die opposite to a longitudinal end of the insert members, and a gate for filling the resin therethrough into the molding die, the gate being formed on an inner wall surface of the molding die opposite to a side of the insert members in a width direction thereof.

Growing community of inventors

Hitachi, Japan

Masafumi Kaga