| 摘要 |
A double-wall pipe, a method of manufacturing the same, and a refrigerant cycle device provided with the same are provided to protect outer and inner pipes from resonation and prevent noise and breakage of the double-wall pipe, by forming a helical groove portion which defines a passage in a bending portion between the outer pipe and inner pipe, each of which part is fixedly secured in the bending portion with a simple structure. A double-wall pipe used in a refrigeration cycle device comprising a compressor, a high pressure heat exchanger, a pressure reducing unit, and a low pressure heat exchanger, the double-wall pipe comprises an outer pipe(161), and an inner pipe(162). The inner pipe is disposed inside of the outer pipe having a projected portion(162b) to form a helical groove portion(162a) having a plurality of helical grooves that are extending in a longitudinal direction. The outer and inner pipes are bending to have a straight portion extending in a straight line, and a bending portion(163b) bending from the straight line. The outer pipe has an inner diameter larger than an outer diameter of an imaginary cylinder which is formed by an outer surface of the projected portion of the inner pipe in the straight portion, and has an outer diameter that is in a range of 1.1 to 1.3 times of the outer diameter of the inner pipe. The projected portion of the inner pipe is pressed and held by the outer pipe in the bending portion, by making contact with the inner side of the outer pipe. High pressure refrigerant flow between the outer pipe and inner pipe, and low pressure refrigerant flow in the inner pipe. |
