Kabushiki Kaisha Toshiba

Denso Corporation

Denso Airs Corporation

Takashi Ono

Yoshiaki Takano

Takahisa Suzuki

Shun Kurata

Fumiaki Nakamura

Hiroki Naganawa

Kinji Ochiai

Hiroki Ohara

Hisao Inoue

Toshitomo Hayami

Katsumi Iguchi

Humio Shibata

Takashi Ishimoto

A double-wall pipe includes an outer pipe, and an inner pipe disposed inside the outer pipe. An outer wall of the inner pipe has thereon a ridge portion, which defines a groove portion extending in a longitudinal direction of the inner pipe. The outer pipe and the inner pipe are bent to have a straight portion extending straightly, and a bend portion bent from the straight portion. In the straight portion, the outer pipe has an inside diameter that is larger than an outside diameter of an imaginary cylinder defined by an outer surface of the ridge portion of the inner pipe. Furthermore, the ridge portion of the inner pipe contacts an inside surface of the outer pipe to be radially squeezed and held by the outer pipe, in the bend portion. The double-wall pipe can be suitably used for a refrigerant cycle device.

Double-wall pipe, method of manufacturing the same and refrigerant cycle device provided with the same

A double-wall pipe includes an outer pipe, and an inner pipe disposed inside the outer pipe. An outer wall of the inner pipe has thereon a ridge portion, which defines a groove portion extending in a longitudinal direction of the inner pipe. The outer pipe and the inner pipe are bent to have a straight portion extending straightly, and a bend portion bent from the straight portion. In the straight portion, the outer pipe has an inside diameter that is larger than an outside diameter of an imaginary cylinder defined by an outer surface of the ridge portion of the inner pipe. Furthermore, the ridge portion of the inner pipe contacts an inside surface of the outer pipe to be readially squeezed and held by the outer pipe, in the bend portion. The double-wall pipe can be suitably used for a refrigerant cycle device.

A furnace for the formation of a black oxide film on the surface of a thin metal sheet is disclosed which comprises a tunnel-like furnace proper provided at one terminal side thereof with an inlet and at the other terminal side thereof with an outlet, conveying means laid inside the furnace proper from the inlet through the outlet thereof for conveying a thin metal sheet from the inlet to the outlet, openable shutter means for partitioning the interior of the furnace proper into at least first and second regions on the front and rear sides respectively in the direction of conveyance of the thin metal sheet, first gas supply means for feeding into the first region on the inlet side of the furnace proper partitioned by the shutter means a mixed gas containing carbon dioxide and carbon monoxide and containing substantially no oxygen or a mixed gas containing carbon dioxide, carbon monoxide, and steam and containing substantially no oxygen, second gas supply means for feeding into the second region on the outlet side of the furnace proper partitioned by the shutter means a mixed gas containing carbon dioxide, carbon monoxide, and oxygen and containing substantially no steam, and heating means for heating the first region to a temperature in the range of 500.degree. to 650.degree. C. and the second region to a temperature in the range of 100.degree. to 300.degree. C.

Furnace for formation of black oxide film on the surface of thin metal

Growing community of inventors

Okazaki, Japan

Takashi Ono