RU2157290C2 - Method for making hollow spherical products with through tubular duct - Google Patents

Abstract

FIELD: plastic metal working, namely manufacture of hollow spherical articles with through duct such as stoppers of ball cocks and other members of lock fitting. SUBSTANCE: two shells are coaxially mounted on central rod of shaping tool. Inner shell has inner diameter equal to that of nominal opening of through duct. It allows to make spheres with through tubular duct. Edges of shell may be mutually joined by means of lap welded joint or shell blank is made with protrusion in its mean portion. Said protrusion is joined with inner surface of shell by lap welded joint. It allows to make spheres with thickened portion of wall designed for making blind groove in it. EFFECT: lowered labor and metal consumption, enhanced quality of products. 3 cl, 8 dwg, 1 exp, 1 tbl

Description

 The invention relates to the processing of metals by pressure and can be used for the manufacture of hollow spherical shaped products with a through tubular channel, for example, plugs of ball valves and other components of valves.

 A known method of manufacturing a hollow sealed ball, comprising crimping the tubular billet and sealing the hole in the hollow ball, and before crimping the end of the tubular billet is heated to forging temperature, the compression is performed by sequentially rolling the end of the tubular billet with a calibrated friction tool, while first the end of the tubular billet is reduced to a diameter equal to the diameter of the ball, then at the end of the reduced section, the hemisphere is run in and from the interface line of the hemisphere with the reduced section of the tube of the billet, the second hemisphere is run into a pinch with a diameter of 0.3 ... 0.5 of the diameter of the ball, the spherical end of the tubular billet is clamped in the spindle and separated from the tubular billet (see, for example, USSR author's certificate N 1 660 812, IPC B 21 D 51/08, 41/04).

 This method is characterized by increased manufacturing complexity and the need to obtain a calibrated channel, which causes the deformation of the hollow ball.

 There is also a known method of manufacturing hollow spherical shaped products with a through tubular channel, including forming a hollow sphere from two shells coaxially mounted on the central core of the forming tool, the diameter of the through holes of the outer shell and the inner diameter of the central shell are made equal to the conditional passage of the through channel (see, for example, European patent EP 0156936, IPC B 21 D 51/08, F 16 K 27/06, 5/08).

 The disadvantage of this method is the need to introduce additional operations associated with the inability to form a tight connection between the inner surface of the spherical shell and the ends of the central shell due to the occurrence of elastic deformations in the spherical shell. Such operations can be various types of welding operations for rigidly connecting the central shell with the outer spherical shell. Due to the possible deformation of the central shell, another option is eliminated for achieving a tight connection between the sphere and the central shell, which consists in increasing the pressing force of the parts by increasing the allowance for the length of the central shell or the allowance for the thickness of the outer.

 Based on the totality of common features, the method according to Europatent EP 0156936, IPC B 21 D 51/08 was selected as a prototype. F 16 K 27/06, 5/08).

 The objective of the invention is to reduce the complexity of manufacturing and metal consumption, the exclusion of deformation of the sphere when performing its thickness for the connection with the drive rotation.

где H - длина наружной обечайки,
D - диаметр сферы,
b - толщина стенки сферы,
d - наружный диаметр внутренней обечайки,
а также тем, что края заготовки наружной обечайки соединяют между собой сварным нахлесточным соединением, либо тем, что заготовку наружной обечайки изготавливают с выступом в средней части, который соединяют с внутренней поверхностью обечайки сваркой, а после формования сферической поверхности в зоне выступа выполняют несквозной паз.The task of the proposed method for the manufacture of hollow spherical shaped products with a through tubular channel, including forming a hollow sphere from two shells coaxially mounted on the central core of the forming tool, the inner shell of which is made with an inner diameter equal to the conditional passage of the through channel, and the height of the inner shell is chosen equal to the distance between the holes in the hollow sphere, which is formed with central holes equal to the outer diameter of the inner seagulls, which length is determined from the relationship:

where H is the length of the outer shell,
D is the diameter of the sphere,
b is the wall thickness of the sphere,
d is the outer diameter of the inner shell,
as well as by the fact that the edges of the outer shell blank are connected by a welded lap joint, or by the fact that the outer shell blank is made with a protrusion in the middle part, which is connected to the inner surface of the shell by welding, and after forming a spherical surface in the protrusion zone, a through groove is made.

где H - длина наружной обечайки,
D - диаметр сферы,
b - толщина стенки сферы,
d - наружный диаметр внутренней обечайки,
обеспечивает достижение герметичности соединения центральной обечайки со сферой за счет обжатия центральной обечайки в процессе формирования сферической оболочки, при этом упругие силы стремятся увеличить натяг между сферической оболочкой и центральной обечайкой. Упрощается процесс сборки и разборки формующего инструмента, исключаются дополнительные операции по герметизации полости сферы.The choice of the height of the inner shell equal to the distance between the holes in the hollow sphere, which is formed with central holes equal to the outer diameter of the inner shell, the length of which is determined from the ratio:

where H is the length of the outer shell,
D is the diameter of the sphere,
b is the wall thickness of the sphere,
d is the outer diameter of the inner shell,
ensures the tightness of the connection of the Central shell with the sphere due to compression of the Central shell in the process of forming a spherical shell, while the elastic forces tend to increase the tightness between the spherical shell and the Central shell. The assembly and disassembly of the forming tool is simplified, additional operations to seal the cavity of the sphere are excluded.

 The connection of the edges of the shell blanks with a welded lap joint makes it possible to produce a hollow sphere with different wall thicknesses, which allows a through groove to be made on the wall thickening and thereby prevent products from entering the sphere cavity, which is a prerequisite for using, for example, ball valves in food , medical, biochemical and other industries.

 The manufacture of a shell blank with a protrusion in the middle part, which is connected to the inner surface of the shell by welding, and after forming hemispheres in the protrusion zone, a through groove is performed, which allows solving the same problem with a lower material consumption, since a large thickness is located only in the through groove zone. In this case, various types of welding can be used.

 The drawings show embodiments of the manufacturing operations of hollow spherical plugs of ball valves. In Fig. 1, an embodiment of manufacturing a spherical shaped article with a tubular channel is shown, and in Figs. Figure 2 shows the assembly resulting from stamping, Fig. 3 shows the construction of a shell made by rolling, followed by joining the joints with a welded lap seam, and Figs. 4 and 5 show the process of stamping balls with an asymmetric wall thickness. In Fig.6. a view of a blank for rolling with a central protrusion is shown, in FIG. 7 shows a view of a rolled preform before stamping; FIG. 8 shows a product with a non-through groove.

 In the manufacture of spherical plugs with a tubular channel (see Fig. 1,2), a stamp is used that contains two half-matrixes 7, a rod 8 is installed in the lower half-matrix. The blanks 1 are rolled and welded along the joint line. After installing the outer and inner blanks, as shown in FIG. 2, set the upper half-matrix 7 and press down to the bottom. In this case, the function of the limiter is performed by the inner preform 1, the radial deformation of which is prevented by the rod 8. After the molding is completed, the rod 8 is pulled out of the stamp by a press and the stamp is disassembled and the finished product 9 is removed.

 To obtain a different thickness product, a blank 1 is used, as shown in FIG. 7, in which a protrusion is made in the middle part, or the workpiece is rolled with an overlap, as shown in Figs. 7, 3, after which the workpiece 1 is welded, as shown in Fig. 3. All subsequent operations are performed similarly to those described above, with the exception of a through groove 10, as shown in FIG. 8.

 Example.

 The proposed method was carried out on hydraulic presses with a maximum force of 250 t and 630 t. Shell blanks were made from sheet material (12X18H10T steel) with a thickness of 3 mm to 14 mm, the joints of which were joined by welding in a protective gas (argon) medium. The test results are shown in the table.

 The proposed method allows to reduce the complexity of manufacturing hollow spherical products, used, for example, as plugs of ball valves, to reduce the consumption of metal due to the use of sheet material and to prevent deformation of the sphere when performing through channels, thereby improving the quality and resource of products, for example ball valves.

Claims (3)

1. A method of manufacturing a hollow spherical shaped product with a through tubular channel, comprising shaping a hollow sphere from two shells coaxially mounted on the central core of the forming tool, the inner of which is made with an inner diameter equal to the nominal passage of the through channel, characterized in that the height of the inner shell is chosen equal to the distance between the holes in the hollow sphere, which is formed with central holes equal to the outer diameter of the inner shell, the length of which redelyayut the relation

where H is the length of the outer shell;
D is the diameter of the sphere;
b is the wall thickness of the sphere;
d is the outer diameter of the inner shell.  2. The method according to claim 1, characterized in that the edges of the outer shell blank are connected by a welded lap joint.  3. The method according to claim 1, characterized in that the blank of the outer shell is made with a protrusion in the middle part, which is connected to the inner surface of the shell by welding, and after forming a spherical surface in the protrusion zone, a through groove is made.

Images