Method for producing a metal connecting accessory

Abstract

The invention relates to a method for producing a cylindrical metal connector, wherein the connector comprises a tubular body with two internally hollow cylindrical areas joined by an intermediate area with a polygonal outer edge. The method is characterised in that the metal connector is produced from a single tubular metal element by means of a step of cold forming using a first tubular expansion tool intended to be in contact with the side wall of the tubular metal element, the first tool being provided with a section comprising a plurality of radially expandable segments shaped to provide the form of the polygonal intermediate section, each segment having a protruding edge. The segments are expanded by the action of a punch, such that, when the punch moves towards the first tool, as the punch is inserted into the first tool, the segments expand towards the side wall of the tubular body to be shaped, thereby forming the intermediate area with a polygonal edge.

Description

[0001] Manufacturing method of a metal splice fitting

[0002] DESCRIPTIVE MEMORY

[0003] OBJECT OF THE INVENTION

[0004] The purpose of this application is to register a manufacturing method for a metal fitting commonly used in fluid channeling installations.

[0005] BACKGROUND OF THE INVENTION

[0006] Male fittings are well known for forming fluid conduction systems. These fittings are formed from a tubular cylindrical body with at least one threaded section to which a machined hexagonal part is attached. Therefore, the fitting is manufactured by individually manufacturing each of these two parts, and in a subsequent step, the cylindrical body and the hexagonal part are joined by means of a welding process.

[0007] As is well known, welding processes require tools and filler materials to join the two parts, making the fittings more costly to manufacture and carrying a risk of defects in the welded area, which means they must be discarded before being marketed.

[0008] Furthermore, the applicant is not currently aware of an invention that has all of the features described herein.

[0009] DESCRIPTION OF THE INVENTION

[0010] The present invention has been developed in order to provide a manufacturing method that is configured as a novelty within the field of application and solves the aforementioned drawbacks, also providing other additional advantages that will be evident from the description that follows.

[0011] It is therefore an object of the present invention to provide a method for manufacturing a cylindrical metal fitting, wherein the fitting comprises a tubular body comprising two internally hollow cylindrical regions joined by an intermediate region with an outer contour of polygonal shape, characterized in that the metal fitting is obtained from a single tubular metal element by means of a cold forming stage, in which a first expanding tool (or also called die) of substantially tubular shape is used, intended to be in contact with the side wall of the tubular metal element, the first expanding tool being provided with a section comprising a plurality of radially extensible segments shaped to provide the shape of the polygonal intermediate section, each of the segments having a projecting rim, which rims are expanded by the action of a punch with a conical termination,such that when the punch moves towards the first expanding tool, as the punch is introduced into the interior of the first expanding tool, the segments extend towards the side wall of the tubular body to be formed, thus forming the intermediate region with a polygonal contour.

[0012] The number of flat faces on the outer surface of the intermediate region is linked to the number of extensible segments present in the first expander tool.

[0013] According to another aspect of the invention, the conical end of the punch may comprise a plurality of diametrical grooves spaced equidistantly apart from each other.

[0014] According to a preferred embodiment, the projecting rim projects outward, such that, during the forming step, said projecting rims act on a region of the inner face of the cylindrical wall of the tubular body to be formed. In an alternative embodiment, the projecting rim projects inward, such that, during the forming step, said projecting rims act on a region of the outer face of the cylindrical wall of the tubular body to be formed.

[0015] According to the invention, the punch is axially movable by means of the first expanding tool (2) by means of the arrangement of automated actuation means that are coupled to the punch itself.

[0016] Thanks to these features, the production process for this type of fitting is simplified, as it does not require welding processes. This means fewer specialized tools are required, resulting in lower costs.

[0017] The manufacturing method described represents, therefore, an innovative structure with structural and constitutive characteristics unknown until now for the purpose for which it is intended, reasons which, together with its practical usefulness, provide it with sufficient grounds to obtain the exclusive privilege that is requested.

[0018] Other features and advantages of the manufacturing method object of the present invention will become evident from the description of a preferred, but not exclusive, embodiment, which is illustrated by way of non-limiting example in the accompanying drawings, in which:

[0019] BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1.- It is a perspective view of a first embodiment of a splicing accessory obtained by the manufacturing method according to the invention;

[0021] Figure 2.- It is a perspective view of a second embodiment of the accessory obtained by the manufacturing method of the invention;

[0022] Figure 3 is a schematic sequential view of a first embodiment of carrying out the method according to the invention; Figure 4 is a schematic sequential view of a second embodiment of carrying out the method according to the invention;

[0023] Figure 5.- It is an elevation view of an embodiment of a punch used in the manufacturing method of the invention;

[0024] Figures 6a and 6b.- Are perspective and longitudinal section views, respectively, of a second embodiment of a punch used in the manufacturing method of the invention;

[0025] Figure 7 is a plan view and cross-section along line AA of a first expander tool used in the manufacturing method of the invention; and

[0026] Figures 8a and 8b.- These are perspective and longitudinal section views, respectively, of a second embodiment of the first expander tool.

[0027] DESCRIPTION OF A PREFERRED EMBODIMENT

[0028] In view of the aforementioned figures and, in accordance with the numbering adopted, one can observe in them an example of a preferred embodiment of the invention, which comprises the parts and elements indicated and described in detail below.

[0029] Furthermore, the terms upper, lower, above, below and the like in the description and claims are used for descriptive purposes and not necessarily to describe relative positions.

[0030] Figure 1 shows a cylindrical metal fitting, generally indicated by the reference (1), which is essentially formed by a tubular body made up of two internally hollow cylindrical regions (10) joined by an intermediate region (11) with a polygonal, preferably hexagonal, contour. It should be mentioned that each of the cylindrical regions (10) may have an internal or external threaded portion intended for coupling a conventional conduit or coupling (not shown) that forms part of an installation for the conduction of fluids, which will not be gone into in greater detail since it does not form part of the invention. Said threaded portions are obtained at a later stage by conventional means, so no further explanation will be given thereof.

[0031] In the case of figure 1, the intermediate region (11) has an outer diameter that protrudes with respect to the outer diameter of the two cylindrical regions (10) while in figure 2, a second embodiment has been represented that differs from the previous one in that it has an intermediate region (11) with a smaller outer diameter with respect to the two cylindrical regions (10).

[0032] The metal joint (1) is obtained from a single tubular and internally hollow metal element by means of a cold forming stage, in which a first expander tool (2) is used, made of a steel with a substantially tubular shape intended to be in contact with the side wall of the tubular metal element.

[0033] With particular reference to the first expander tool (2), it is provided with a section comprising a plurality of radially extensible segments (20) shaped to provide the shape of the polygonal intermediate section. Each of the segments has a projecting rim (21), each of which is expanded by the action of a punch (3) with a conical or truncated conical termination (depending on whether a compression or traction deformation is applied), such that when the punch (3) moves in the direction towards the first expander tool (as indicated by arrows (f) in Figures 3 and 4), as the punch is introduced inside the first expander tool (2), the extension of the segments (20) takes place towards the side wall of the tubular body to be formed, thus forming the intermediate region of polygonal contour.

[0034] The number of segments (20) of the first expanding tool (2) corresponds to the number of faces of the intermediate region (11) of polygonal contour, so that, in the example shown in the figures, the number of segments is six. It will be evident that the number of segments may vary depending on the number of faces desired in the manufacture of the metal joint (1). As can be seen in greater detail in figure 5, the conical termination (30) of the punch (3) comprises a plurality of diametrical grooves (31) equidistantly spaced from each other, being made of a high hardness steel material. Such punch can be axially moved by actuating means, for example, pneumatic, mechanical or electromechanical actuation of known type.

[0035] Figures 6a and 6b show another design option for the punch (3) used to manufacture the metal joint, the common parts of which have the same numerical references as in the example shown above, in which it is devoid of the plurality of grooves. On the contrary, this punch (3) has a plurality of flat faces (32) distributed radially at its conical end (30). Figure 6b shows how a blind hole (33) is provided, intended to be coupled by threading to actuating means.

[0036] Figures 8 and 8b show a second preferred embodiment of the expander tool (2) used for manufacturing the metal joint, in which the through hole (22) through which the punch (3) is introduced has a complementary shape and is adapted to the punch shown in Figures 6a and 6b.

[0037] In an embodiment of the method of the invention shown in Figure 3, the projecting edge (21) projects outwards, such that, during the forming stage, such projecting edges (21) of the segments (20) act on a region of the inner face of the cylindrical wall of the tubular body (100) to be formed, in this case the punch shown in Figure 5 is used.

[0038] On the other hand, a second way of carrying out the manufacturing method shown in figure 4, consists in the fact that the projecting edge (21) protrudes inwards, such that, during the forming stage, such projecting edges act on a region of the outer face of the cylindrical wall of the tubular body (100) to be formed. Furthermore, in this embodiment, the punch (3) has a truncated conical termination that will act on an inclined surface of the segments (20), such that they will move in a perpendicular direction towards the wall of the tubular body (100), that is, a radial compression is carried out to obtain the intermediate region (11) with a polygonal contour.

[0039] The details, shapes, dimensions and other accessory elements used in the manufacturing method of the invention may be conveniently replaced by others that do not deviate from the scope defined by the claims included below.

Claims

CLAIMS 1. Method for manufacturing a cylindrical metal joint, wherein the joint comprises a tubular body comprising two internally hollow cylindrical regions (10) joined by an intermediate region (11) with an outer contour of polygonal shape, characterized in that the metal joint is obtained from a single tubular metal element by means of a cold forming stage, in which a first expanding tool (2) with a substantially tubular shape is used which is intended to be in contact with the side wall of the tubular metal element, the first expanding tool (2) being provided with a section comprising a plurality of radially extensible segments (20), which are shaped to provide the shape of the polygonal intermediate section, each of the segments (20) having a projecting rim, which rims are expanded by the action of a punch (3) with a conical or truncated conical termination,such that when the punch (3) moves towards a through hole (22) present in the first expanding tool (2), as the punch (3) is introduced into the first expanding tool through the through hole (22) the extension of the segments (20) towards the side wall of the tubular body to be formed takes place, thus forming the intermediate region (11) with a polygonal outer contour.

2. Method of manufacturing a cylindrical metal joint according to claim 1, characterized in that the conical end (3) of the punch (30) comprises a plurality of diametrical grooves spaced equidistantly from each other.

3. Method of manufacturing a cylindrical metal joint according to claim 1, characterized in that the projecting rim protrudes outwards, such that, during the forming stage, such projecting rims act on a region of the inner face of the cylindrical wall of the tubular body to be formed.

4. Method for manufacturing a cylindrical metal fitting according to claim 1, characterized in that the projecting edge projects inwards, such that, during the forming stage, such projecting edges act on a region of the outer face of the cylindrical wall of the tubular body to be formed.

5. Method of manufacturing a cylindrical metal joint according to claim 1, characterized in that the punch (3) is axially movable with respect to the first expanding tool (2) by automated actuation means.

6. Method of manufacturing a cylindrical metal joint according to claim 1, characterized in that the punch (3) has at its conical end (30) a plurality of flat faces (32) distributed radially.

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