A hollow coil spring is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

A hollow coil spring is made of a hollow wire in which a terminal sealed portion is formed on an end portion of the wire. The terminal sealed portion has a rotationally symmetric shape in which an axis passing through the center of the wire is the symmetric axis. The hollow coil spring includes an end wall portion, and an end face arc-shaped curved surface. The end wall portion includes an end face perpendicular to the axis. A distal-end-center closure portion is formed on the axis at the center of the end wall portion. A spring seat includes a base member and a sheet member. An end turn portion of the hollow coil spring is in contact with the sheet member. The end face of the end turn portion is opposed to a stopper wall of the spring seat.

A fitting to be connected to a pipe includes: a first member; a second member coupled by screw coupling with the first member; and a ferrule placed in an accommodation space formed by an inner circumferential surface of the first member, an inner circumferential surface of the second member, and an outer circumferential surface of the pipe. The ferrule has a rising portion including a first end portion, a pressed portion located closer to a second end portion than the rising portion, and an intermediate portion including a portion where an inner diameter is greater than the first end portion and the second end portion, the intermediate portion connecting together the rising portion and the pressed portion. The first member has a first tapered inner circumferential surface, which is an inner circumferential surface having a tapered shape, to be in contact with the first end portion of the ferrule. The second member has a pressing portion for pressing at least a portion of the pressed portion of the ferrule. The accommodation space has a first clearance space for accommodating the ferrule therein and allowing the rising portion to rise so as to increase an angle of the rising portion with respect to the outer circumferential surface of the pipe.

A fitting to be connected to a pipe includes: a first member; a second member coupled by screw coupling with the first member; and a ferrule placed in an accommodation space formed by an inner circumferential surface of the first member, an inner circumferential surface of the second member, and an outer circumferential surface of the pipe. The ferrule has a rising portion including a first end portion, a pressed portion located closer to a second end portion than the rising portion, and an intermediate portion including a portion where an inner diameter is greater than the first end portion and the second end portion, the intermediate portion connecting together the rising portion and the pressed portion. The first member has a first tapered inner circumferential surface, which is an inner circumferential surface having a tapered shape, to be in contact with the first end portion of the ferrule. The second member has a pressing portion for pressing at least a portion of the pressed portion of the ferrule. The accommodation space has a first clearance space for accommodating the ferrule therein and allowing the rising portion to rise so as to increase an angle of the rising portion with respect to the outer circumferential surface of the pipe.

A cylinder housing 12 includes a cylindrical cylinder portion 21 which extends in the direction of a center axis line Z and a bent portion 22 which is bent with respect to the cylinder portion 21 and extends inward in a radial direction from an end portion of the cylinder portion 21, the cylinder portion 21 includes a first cylinder portion 25 and a second cylinder portion 26 which is located on the side of the bent portion 22 in the first cylinder portion 25 and is connected to the bent portion 22, a thickness B of the second cylinder portion 26 is equal to or larger than a thickness A of the first cylinder portion 25, and a thickness C of the bent portion 22 is larger than the thickness A of the first cylinder portion 25.

A magnesium alloy thick and thin tube butting mechanism is disclosed in the utility model and includes a tube butting mold, a tube butting mandrel, and a hydraulic actuator. The tube butting mold has a mold heating component used for magnesium alloy tube to enter a tube wire drawing mold. A material is heated. The magnesium alloy thick and thin tube butting mechanism may further include a tube heating component configured to pre-heat the magnesium alloy tube before the magnesium alloy tube enters a tube mold.

A magnesium alloy thick and thin tube butting mechanism is disclosed in the utility model and includes a tube butting mold, a tube butting mandrel, and a hydraulic actuator. The tube butting mold has a mold heating component used for magnesium alloy tube to enter a tube wire drawing mold. A material is heated. The magnesium alloy thick and thin tube butting mechanism may further include a tube heating component configured to pre-heat the magnesium alloy tube before the magnesium alloy tube enters a tube mold.

A strut (I) comprising an elongated beam portion (2) and at least one connecting end portion (3), where the elongated beam portion (2) is a tubular structure having an external circumference (C), and the connecting end portion (3) is integral with the elongated beam portion (2) and is comprised of a folded and flattened end portion of the tubular structure, in which diametrically opposite inward fold lines (5) meet between flattened parts (3a, 3b) of the end portion of the tubular structure, so that the resulting connecting end portion (3) comprises four material layers, and where the connecting end portion has a width (w) in a direction transverse to a longitudinal centreline (L) of the connecting end portion, where w>CI 4, and a method (I 00) of manufacturing a strut (I) comprising the steps of providing (IOI) a tubular element (IO) having an external circumference (C) and forming (I02; I03) a connecting end portion (3) at an end of the tubular element (IO), wherein the connecting end portion is formed by folding (I02) and flattening (I03) a portion (3′) of the tubular element (IO), wherein the folding (I02) is performed by deforming the material in said portion (3′) so as to form inward fold lines (5), and pushing them from diametrically opposite sides in a direction (pI) toward the centre (X) of the tubular element until they meet, and the flattening (I03) is performed by pressing the thus folded portion (3′) toward the centre (X) of the tubular element, from opposite directions (p2) perpendicular to the direction of pushing (pI), whereby an end portion (3) comprising four material layers is obtained.

A strut (I) comprising an elongated beam portion (2) and at least one connecting end portion (3), where the elongated beam portion (2) is a tubular structure having an external circumference (C), and the connecting end portion (3) is integral with the elongated beam portion (2) and is comprised of a folded and flattened end portion of the tubular structure, in which diametrically opposite inward fold lines (5) meet between flattened parts (3a, 3b) of the end portion of the tubular structure, so that the resulting connecting end portion (3) comprises four material layers, and where the connecting end portion has a width (w) in a direction transverse to a longitudinal centreline (L) of the connecting end portion, where w>CI 4, and a method (I 00) of manufacturing a strut (I) comprising the steps of providing (IOI) a tubular element (IO) having an external circumference (C) and forming (I02; I03) a connecting end portion (3) at an end of the tubular element (IO), wherein the connecting end portion is formed by folding (I02) and flattening (I03) a portion (3′) of the tubular element (IO), wherein the folding (I02) is performed by deforming the material in said portion (3′) so as to form inward fold lines (5), and pushing them from diametrically opposite sides in a direction (pI) toward the centre (X) of the tubular element until they meet, and the flattening (I03) is performed by pressing the thus folded portion (3′) toward the centre (X) of the tubular element, from opposite directions (p2) perpendicular to the direction of pushing (pI), whereby an end portion (3) comprising four material layers is obtained.

Provided are a method of manufacturing an orifice and an orifice manufactured by the same. An object of the present invention is to provide a method of manufacturing an orifice spraying a very small amount of fluid in ultra-high pressure and very low temperature environments and reducing a volume and a mass, and an orifice manufactured by the same. More specifically, an object of the present invention is directed to providing a method of manufacturing an orifice capable of manufacturing an orifice effectively realizing a desired hydraulic performance by a simple manufacturing method of allowing a channel region having a cross section close to a rectangular shape to be formed by pressing a part of a capillary pipe, and an orifice manufactured by the same.