Abstract: A heat exchanger having excellent heat exchanging performance is obtainable by a simple production technique and at a low cost. This is achieved by providing a fin member and by increasing heat conductivity between the fin member and a meandering pipe body. Further, the heat exchanger is made compact for high degrees of layout freedom, enabling the heat exchanger to be installed in a tight space. Engagement grooves (8) are provided in both end surfaces (6, 7), which are opposite to each other, of a fin member (5) in which fins (4) are parallel arranged. Straight pipe sections (2) are parallelly arranged, with gaps (16)in between, in the engagement grooves (8) of the fin member (5). The straight pipe sections (2)a are connected at bent sections (3). A pair of meandering sections (11, 12) is arranged opposite to each other with an insertion gap (17) of the fin member (5) in between.

Abstract: A heat exchanger having excellent heat exchanging performance is obtainable by a simple production technique and at a low cost. This is achieved by providing a fin member and by increasing heat conductivity between the fin member and a meandering pipe body. Further, the heat exchanger is made compact for high degrees of layout freedom, enabling the heat exchanger to be installed in a tight space. Engagement grooves are provided in both end surfaces, which are opposite to each other, of a fin member in which fins are parallel arranged. Straight pipe sections are parallelly arranged, with gaps in between, in the engagement grooves of the fin member. The straight pipe sections a are connected at bent sections. A pair of meandering sections is arranged opposite to each other with an insertion gap of the fin member in between. On of the meandering sections and the other meandering section are connected by a connection pipe to form a meandering pipe main body.

Abstract: It is an object of this invention to obtain a heat conduction pipe superior in corrosion resistance as well as heat exchange efficiency between fluid flowing respectively through an inside and an outside for great heat radiation property and endothermic characteristics. It is also object of this invention to form the heat conduction pipe superior in the corrosion resistance as well as the heat radiation property and endothermic characteristics at inexpensive price. To achieve the above, at least single resin coating layer is formed on an outer circumferential surface of a metal pipe, a metal fin member is spirally wound on an outer circumferential surface of the resin coating layer with a side end surface the metal fin member in contact. The winding contact portion is made to encroach a surface of the resin coating layer to form the heat conduction pipe.

Abstract: It is an object of this invention to obtain a heat conduction pipe superior in corrosion resistance as well as heat exchange efficiency between fluid flowing respectively through an inside and an outside for great heat radiation property and endothermic characteristics. It is also object of this invention to form the heat conduction pipe superior in the corrosion resistance as well as the heat radiation property and endothermic characteristics at inexpensive price. To achieve the above, at least single resin coating layer is formed on an outer circumferential surface of a metal pipe, a metal fin member is spirally wound on an outer circumferential surface of the resin coating layer with a side end surface the metal fin member in contact. The winding contact portion is made to encroach a surface of the resin coating layer to form the heat conduction pipe.

Abstract: Connection structure for connecting a piping used in automobiles or the like to a ring joint for providing highly reliable gas-tightness. The ring joint includes a ring joint body including a fitting hole for an eyebolt, the fitting hole being piercingly formed in an axial core portion of the ring joint body and in continuation from an annular recessed groove formed inside the ring joint body, and a flow path extending in a direction perpendicular to and intersecting with the fitting hole. A branch pipe is formed as a unitary body with the ring joint body and arranged in a direction perpendicular to and intersecting with the eyebolt. A piping for insertion into the branch pipe has an outer peripheral surface covered with resin, and the resin of the outer peripheral surface of the piping and an inner peripheral surface of the branch pipe are fixedly welded to one another.

Abstract: This invention provides a connection structure for connecting a piping used in automobiles or the like to a ring joint for providing highly reliable gas-tightness. The connection can be performed with an easy and inexpensive method and also can provide excellent productivity and safety. The connection structure has highly reliable disengagement resistance.