Abstract: 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.

Abstract: 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.

Abstract: A method of manufacturing a double pipe includes a step of inserting a straight inner pipe into a straight outer pipe such that the inner pipe and the outer pipe are positioned at a predetermined relative position, a step of fixing a first end portion of the outer pipe to the inner pipe so as to form a first fixing portion, a step of bending the outer pipe and the inner pipe at the same time at a predetermined portion so as to form at least one bending portion after the fixing step of the first end portion, and a step of fixing a second end portion of the outer pipe to the inner pipe so as to form a second end portion after the bending.

Abstract: A compound tube is disclosed that includes an outer tube and an inner tube disposed in the outer tube. A passage is defined between the outer tube and the inner tube. Various methods of joining the outer tube to the inner tube are disclosed.

Abstract: 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.

Abstract: A pipe joint unit includes a first pipe member with a male joint, a second pipe member with a female joint, and a pipe joint member coupling the first pipe member and the second pipe member. The male joint is received in the female joint such that an outer peripheral surface of the male joint is opposed to an inner peripheral surface of the female joint. The pipe joint member includes an engagement part that is elastically displaceable in the radial direction, and engages with the first and second pipe members. The male joint and the female joint have rotation restricting parts on the outer peripheral surface and the inner peripheral surface, respectively, for restricting relative rotation of the first and second pipe members.

Abstract: A pipe joint unit includes a first pipe member with a male joint, a second pipe member with a female joint, and a pipe joint member coupling the first pipe member and the second pipe member. The male joint is received in the female joint such that an outer peripheral surface of the male joint is opposed to an inner peripheral surface of the female joint. The pipe joint member includes an engagement part that is elastically displaceable in the radial direction, and engages with the first and second pipe members. The male joint and the female joint have rotation restricting parts on the outer peripheral surface and the inner peripheral surface, respectively, for restricting relative rotation of the first and second pipe members.

Abstract: A compound tube is disclosed that includes an outer tube and an inner tube disposed in the outer tube. A passage is defined between the outer tube and the inner tube. Various methods of joining the outer tube to the inner tube are disclosed.

Abstract: A pipe joint has a joint main body, a union nut connected to the joint main body, and a lock ring. The lock ring has a tubular wall, and a first axial end and a second axial end of the tubular wall are deformable by inner walls of tapered hole portion of the joint main body and the union nut. The lock ring has a first tapered opening portion providing a first groove for receiving a first end of a first pipe member and a second tapered opening portion providing a second groove for receiving a second end of a second pipe member, in a radial inside of the tubular wall. A radial outer surface of the first tapered opening portion and a radial outer surface of the second tapered opening portion are tapered such that the first groove and the second groove are narrowed toward its ends, respectively.

Abstract: A method of manufacturing a double pipe includes a step of inserting a straight inner pipe into a straight outer pipe such that the inner pipe and the outer pipe are positioned at a predetermined relative position, a step of fixing a first end portion of the outer pipe to the inner pipe so as to form a first fixing portion, a step of bending the outer pipe and the inner pipe at the same time at a predetermined portion so as to form at least one bending portion after the fixing step of the first end portion, and a step of fixing a second end portion of the outer pipe to the inner pipe so as to form a second end portion after the bending.

Abstract: A method of manufacturing a grooved pipe includes a pressing step and a longitudinally displacing step. The pressing step presses a grooving tool toward an outer surface of a wall of a pipe in a radially inward direction of the pipe at a location, which is separated by a predetermined distance from an end portion of the pipe. The longitudinally displacing is performed by longitudinally displacing at least one of the grooving tool and the pipe relatively in a longitudinal direction of the pipe while pressing the grooving tool toward the outer surface of the wall of the pipe to form a groove portion, which is recessed from the outer surface of the wall of the pipe. The method is suitably used for forming an inner pipe of a double-wall pipe.

Abstract: 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.

Abstract: A double-wall pipe includes an outer pipe provided with first and second openings, respectively, at first and second end parts of the outer pipe in a pipe longitudinal direction, and an inner pipe inserted in the outer pipe to define a passage between the outer pipe and the inner pipe. An inlet portion is connected to the outer pipe to communicate with the passage through the first opening, and an outlet portion is connected to the outer pipe to communicate with the passage through the second opening. In the double-wall pipe, the outer pipe and the inner pipe can be disposed to define an expanded portion having an expanded sectional area in the first passage, and the expanded portion can be provided at least at a portion near the inlet portion and the outer portion. The inner pipe can be provided with plural grooves in the double-wall pipe.