A mandrel for pipe bending machine has an elongated body (3) with a first end connected to a mandrel rod and a second end, opposite to the first, in which there is a spherical seat (8), several intermediate articulated elements (10) and a terminal articulated element (11). Each intermediate joint element (10) and the terminal joint element (11) have a peripheral part (12) configured so as to lean against the inner wall of a pipe (T) to be bent. Each intermediate articulated element (10) has a cup-shaped part (13) in one piece, and a stem (19) extending externally from it, and a spheroidal part (21) in one piece, configured so as to be introduced in a cup-shaped part (13) of a previous intermediate articulated element (10).

Tightly-coiled helical ducts for centrifugal air separators may be formed with the tools and methods disclosed herein. A helical coil toolset includes a helically grooved mandrel and an entry block. The helical groove of the mandrel has a small helix inside diameter relative to a width of the helical groove. The entry block has a guide channel to guide a tube to the helical groove and a mandrel channel to receive the mandrel. Methods include forming tubing into a tightly-coiled helical duct by filling a tube with fine particles, positioning the tube in the helical groove of a helically grooved mandrel, fixing the tube relative to the mandrel, assembling an entry block around the tube and around the mandrel, and bending the filled tube around the helically grooved mandrel into the tightly-coiled helical duct by rotating the mandrel relative to the entry block.

Provided is a device for manufacturing a bent pipe, the device being capable of reducing buckling. The device including: an inner core metal arranged inside a first pipe; and a bending mold to bend the first pipe. The inner core metal includes: an inner core metal body; a first inner movable portion coupled to the inner core metal body and swingable around a first rocking shaft orthogonal to a central axis of the inner core metal body; and a second inner movable portion coupled to the first inner movable portion and swingable around a second rocking shaft parallel to the first rocking shaft. The first inner movable portion has an enlarging diameter portion enlarged in diameter toward the second inner movable portion. The bending mold causes an inner surface of the first pipe to press the first inner movable portion and the second inner movable portion.

One aspect of the present disclosure is a manufacturing device by which the bent pipe is obtained by bending a double pipe. The device includes inner and intermediate core metals, a bending mold, and a controller. The controller executes: a first bending process in which first and second pipes are bent by the bending mold in a first direction in a first area of the double pipe where the inner and intermediate core metals are placed; a second bending process in which the first and second pipes are bent, after the first bending process, by the bending mold in a second direction in a second area of the double pipe where the inner and intermediate core metals are placed; and a first bending-back process in which the second pipe is bent, after the first bending process, in a direction opposite to the first direction in the first area.

One aspect of the present disclosure is a manufacturing device for a bent pipe by which the bent pipe is obtained by bending a double pipe. The manufacturing device for a bent pipe includes an inner core metal, an intermediate core metal, a bending mold, and a controller. The controller executes a first bending process, a second bending process, and a re-bending process. In the first bending process, a first pipe and a second pipe are bend in a first direction in a first area. In the second bending process, the first pipe and the second pipe are bent in a second direction in a second area. The second area has more distance from a coupling portion than the first area does. In the re-bending process, the second pipe is bent in the same direction as the second direction in the second area.

A shaping method for a double pipe includes: bending the double pipe with a specified curvature to form a bent portion in the double pipe; and arranging the bent portion on a first shaping die having a first shaping surface at a position biased inward or outward in a curvature radius direction of the bent portion relative to the first shaping surface, wherein the first shaping surface is configured to shape a first outer surface of both outer surfaces of the bent portion that are located on both sides of a plane including a central axis of the bent portion, and pressing the bent portion arranged on the first shaping die by a second shaping die having a second shaping surface configured to shape a second outer surface of the both outer surfaces of the bent portion.

A variable-diameter full-support mandrel structure with a slider-type cross section for preventing a reverse rotation of a ratchet wheel includes a movable mandrel segment and a straight shank, and the movable mandrel segment and the straight shank are connected through a quick-disconnect universal joint. A rotating shaft of the movable mandrel segment is provided with a connecting rod mounting flange, a ratchet wheel, a reverse ratchet wheel, a bearing, and a limit clamp ring in sequence. An outer ring of the bearing is provided with a pawl mounting frame. The connecting rod mounting flange and the pawl mounting frame are respectively hinged to a long connecting rod and a short connecting rod, and the long connecting rod and the short connecting rod are hinged to slider components in an outer ring. The slider component has a Z-shaped structure composed of two layers of arc blocks.

A variable-diameter full-support mandrel structure with a slider-type cross section for preventing a reverse rotation of a ratchet wheel includes a movable mandrel segment and a straight shank, and the movable mandrel segment and the straight shank are connected through a quick-disconnect universal joint. A rotating shaft of the movable mandrel segment is provided with a connecting rod mounting flange, a ratchet wheel, a reverse ratchet wheel, a bearing, and a limit clamp ring in sequence. An outer ring of the bearing is provided with a pawl mounting frame. The connecting rod mounting flange and the pawl mounting frame are respectively hinged to a long connecting rod and a short connecting rod, and the long connecting rod and the short connecting rod are hinged to slider components in an outer ring. The slider component has a Z-shaped structure composed of two layers of arc blocks.

One aspect of the present disclosure is a manufacturing device for a bent pipe by which the bent pipe is obtained by bending a double pipe. The manufacturing device for a bent pipe includes an inner core metal, an intermediate core metal, a bending mold, and a controller. The controller executes a first bending process, a second bending process, and a re-bending process. In the first bending process, a first pipe and a second pipe are bend in a first direction in a first area. In the second bending process, the first pipe and the second pipe are bent in a second direction in a second area. The second area has more distance from a coupling portion than the first area does. In the re-bending process, the second pipe is bent in the same direction as the second direction in the second area.

A device (10) is disclosed for bending hollow structural components (100), in particular pipes, having a mandrel shaft (40) for receiving a receiving element (20), wherein a row of at least two ball joints (30, 30′) connected with each other can be inserted into the receiving element (20) at its end, wherein the row of ball joints (30, 30′) is preferably lockable by a ball-and-socket joint (70) at an end located opposite the receiving element (20), wherein each ball joint (30, 30′) of the row is circumferentially enclosed by a shingle (50, 50′) and the ball-and-socket joint (70) is circumferentially enclosed by an end shingle (60) and the shingles (50, 60) overlap each other at least in portions.