DE1057054B - Lubrication process for hot extrusion of metallic hollow profiles such as pipes - Google Patents

Description

For the sake of simplicity, reference is made in the description to the production of tubes, although the invention can also be used for the production of other hollow profiles which are hot-extruded by means of a dome.

As is well known, when hot extrusion of metal pipes is a hollow, heated in the transducer introduced press block pressed out by means of a press pin through an annular opening, the outside is limited by the press die and inside by the outer surface of the mandrel. The thorn is on many times arranged a mandrel bar which is displaceable independently of the ram. The ram has in In this case, a hole for the passage of the dome or the mandrel rod.

After the hollow block has been inserted into the transducer, the mandrel is pushed through the bore from behind of the press block advanced so far that the front part of the mandrel goes beyond the press block into the die opening protrudes. Then the hollow block is pressed by means of the ram, the mandrel either is moved with the punch or held during the working stroke of the punch.

To lubricate the mandrel, a lubricant is placed between the bore of the press block and the surface of the mandrel brought. According to a well-known proposal, a substance is used as a lubricant which is listed under the influence of the pressing temperature melts, but remains viscous. This property has z. B. Glass. For the sake of simplicity, only glass is used in the rest of the description.

So far, efforts have been made to distribute the lubricant as evenly as possible over the entire bore of the press block. The lubricant is generally in solid form, e.g. B. as ge cast or pressed tube, as a fabric, as a pile or as a powder.

* It has often been found, however, that the lubrication is inadequate towards the end of the pressing process, especially when blocks of greater length are being pressed. The consequences are rapid wear and tear of the dome on its rear part and defects on the inside of the pipe part that was pressed last. To avoid these deficiencies, the pressing process has hitherto been interrupted before the entire or almost the entire press block was pressed out. This results in a meta loss.

The invention is intended to remedy these deficiencies. It should make it possible that between the There is still a sufficient amount of lubricant in the mandrel and the bore of the press block, when the end part is squeezed out.

In connection with the aforementioned lubrication of the dome by a tough lubrication process at the pressing temperature

in hot extrusion

of metallic hollow profiles,

like pipes

Applicant:

Comptoir Industriel d'Etirage

et Profilage de Metaux,

Paris

Representative:
Dr. GW Lotterhos and Dr.-Ing. HW Lotterhos,

Patent attorneys,
Frankfurt / M., LichtenSteinstr. 3

Claimed priority:
France 6 September 1957

Jean Buffet, Beaumont, Seine-et-Oise (France),
has been named as the inventor

liquid lubricant is already known, too a sheet of glass surrounding the mandrel on the end face of the press block adjacent to the punch to arrange. The aim of this measure is to make it easier to loosen the dome at the end of the pressing process.

It has been found that a simple lubricant disc, which rests against the flat rear surface of the press block is not sufficient to counteract the End of the pressing process required additional Ensure lubrication.

The lubrication method according to the invention in the hot extrusion of metallic hollow profiles, such as pipes, using a lubricant that becomes viscous at the pressing temperature, such as Glass, in the form of a compact body, a fiber structure, Fabric od. The like. Among other things, between the bore of the PreßWockes and the press mandrel is introduced before pressing, is characterized in that a supply of lubricant in one surrounding the press mandrel, for. B. funnel-shaped extension of the ram facing The end of the press block bore is housed.

It is known per se that the end of a hollow press block facing the press ram is funnel-shaped to shape so that the bore of the press

909 51Q / 189

Claims (1)

3 4 Blockes brought into a widening cavity and by means of the ram 1 through the goes. This funnel-shaped cavity is, however, pressed out in the die 10. known case for receiving a corresponding The "Jetall des Preßblockcs 4 flows through the of conically shaped end of the ram and die 10 and mandrel 3 limited space, not as a space for receiving a lubricant 5 whereby the tube 11 is formed. The lubrication is Supply. secured on the one hand by the glass in front of the die The ring or the cuff can be a compact initially laid disc, on the other hand by the Glass body or made of glass fabric or glass fiber glass d ^ s drawn on the mandrel tube 8. While be educated. Preferably the lubricant of the pressing process melts the glass of the sleeve 7 stock, which is housed in the extension, according to io ümT of the "rear part of the Hohres 8 partially and Kind of a cuff formed, one of which fills the rear, the enlargement 6 au.s _J _ ^ This becomes- e-'m The end face of the press block is at least partially formed with lubricant supply 12, which has a perfect ^, has covering ring edge. The extension at the rear - lubrication towards the end of the pressing process secures Ren part of the press block can be used in a known manner by cutting or non-cutting machining, e.g. good lubrication between the rear face in the manufacture of the bore of the press block, flat of the press block 4 and the press disk 2 of the be generated. Rubber stamp*; 1. The invention is hereinafter based on the drawing claims
explained. It shows Fig. 1 schematically in longitudinal section the mandrel at 20 1. Lubrication process in hot extrusion its introduction into the press block, from metallic hollow profiles, such as pipes, under Fig. 2 is a longitudinal section through the Preßvorrich- using a counting at the pressing temperature in the position during pressing. liquid lubricant, such as glass, in The compression ram 1 and its compression disk 2 form a compact body, a fiber the mandrel 3 passed through in a known manner. 25 formed, tissue od. Like., Among other things The press block 4 has an axial bore 5 and between the bore of the press block and the its rear end has an extension 6. Pressing mandrel is inserted before pressing, so that Before the start of pressing is first on the mandrel 3 is characterized by that a supply (7) of the Pulled up glass sleeve 7, which is designed to surround the lubricant in a press mandrel (3) that they at least partially remove the extension 6, e.g. B. funnel-shaped extension (6) of the fill and part of the rear surface of the press ram fl, 2) facing the end of the blockes 4 can cover. Then a pipe or press block bore (5) is accommodated. Tube 8 made of glass fabric, the outer diameter of which is 2. Lubricant supply according to Claim I ₁ the diameter of the bore 5 of the press block 4 characterized in that it is in the manner of a sleeve corresponds, drawn onto the mandrel 3. Then the 35 with one of the rear end face of the press block Mandrel 3 inserted into the press block 4 or the press ring at least partially overlapping block 4 pushed onto the mandrel 3. is trained. After a pane of glass in the receptacle 9 before the die 10 is placed, the documents considered on the mandrel 3: The press block 4 located in the receiver 9 is inserted into the 40 German Patent No. 610 369. 1 sheet of drawings © 909 510-89 5.59