DE1256518B - Heatable press die for hot extrusion production of hollow cylindrical parts for further processing into wheel rims from preformed raw parts made of wrought alloys - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

B21k

German KL: 49i-8

Number: 1256 518

File number: R 364031 b / 49 i

Filing date: October 23, 1963

Opened on: December 14, 1967

The invention relates to heatable press dies for the hot extrusion production of hollow cylindrical parts for further processing into wheel rims from preformed raw parts made of wrought alloy, in particular from Aluminum.

From the French patent specification 1278 208 there are already heatable press dies for hot flow production Hollow cylindrical parts for further processing into wheel rims from preformed raw parts made of wrought alloy, in particular made of aluminum, with an approximately central intermediate floor and on both sides of it extending hollow aprons with axially parallel inner ribs became known, which consist of a movable Extrusion die with extrusion shoulder and a fixed lower die exist that Is constructed in several parts and comprises an extrusion counter ram with extrusion shoulder, in which the Ejector is arranged, the counter punch of one of the extrusion gap forming, centered arranged ring part is surrounded, the opposite of an expansion below the extrusion gap the extrusion die and the two extrusion dies also form the opposing shape of the ribs have and are guided to one another.

The ejection of the finished hollow cylindrical parts takes place in these known heatable parts Press dies in such a way that after the end of the hot extrusion process the movable Extrusion ram moved back to its upper starting position, while at the same time the finished workpiece is still held in the press die by means of a workpiece hold-down device. Has the extrusion ram When it reaches its uppermost position, the workpiece hold-down device is also in its upper starting position withdrawn. Then a workpiece ejector moves, which during the Warm extrusion process had assumed a lower limit position, in which it was on the one hand as a blank centering mandrel served and on the other hand the lower end of the annular die space for the formed the downwardly protruding hollow skirt of the workpiece, relative to the one with the fixed lower die firmly connected extrusion counter punch upwards and thereby pushes the workpiece so far up from the press die from that this is removed and fed to a further processing stage can be.

Apart from the fact that due to the presence of a relative to the movable extrusion die movable Workpiece hold-down device and the presence of a two-part workpiece ejector these known press dies in their constructive heatable press die

for hot extrusion production of hollow cylindrical parts for further processing into wheel rims from preformed raw parts made from wrought alloys

Applicant:

Reynolds Metals Company,

Richmond, Va. (V. St. A.)

ίο representative:

Dipl.-Ing. R. Holzer, patent attorney, Augsburg, Philippine-Welser-Str. 14th

Named as inventor:

Paul Rowan O'Brien, Anchorage, Ky. (V. St. A.)

Claimed priority:
V. St. ν. America of October 24, 1962 a "(232 691)

Construction is very complicated and consequently expensive to manufacture and maintain, in particular the workpiece hold-down device, which can be moved relative to the movable extrusion ram, is a constant source of interference The one that moves back upwards after the hot extrusion process has been completed, movable extrusion ram has namely despite the presence of the workpiece hold-down always striving to pull the workpiece out of the die cavity with it. Since the mutual guidance of the movable extrusion die on the one hand and the extrusion counter ram containing lower die on the other hand only over part of the stroke of the movable extrusion die by the interaction of a bore of this movable extrusion die and of the part of the workpiece ejector serving as a blank centering mandrel is ensured, in particular in the last part of the return movement of the extrusion ram into its upper starting position the risk that the workpiece, if the workpiece hold-down does not function properly has met, between the movable extrusion die and the lower die slightly tilted and thereby damage and / or at least impairment of its surface quality learns.

The invention aims to solve the problem, in the case of press dies of the construction just outlined

709 708/11 +

3 4

art shows a simpler and therefore a working position in terms of manufacturing, in which the movement and maintenance cheaper construction is fully withdrawn under the terms of the extrusion ram and the surrounding ring part is partially lifted from the movable extrusion ram, taking along the work-dependent workpiece hold-down device and a scho-piece .
Nenderen workpiece ejection with as little as possible 5 The raw part coming to be processed in the press friction between workpiece and die designed according to the invention consists of len, so that workpiece ejection is quicker and easier despite the lower ejection forces made of a wrought alloy, for example aluminum , and has a cylindrical circumference and is completely trouble-free. substantial flat upper and lower end faces.

In the sense of solving this problem, the erio After appropriate preheating, the blank

finding of a heatable press die for hot brought into the press die 60, which in its individual

Extrusion molding of hollow cylindrical parts for clarity in FIGS. 1 to 9 of the drawings

processing into wheel rims from preformed raw material.

parts made of wrought alloy, in particular aluminum, the press die 60 designed according to the invention with an approximately central intermediate floor and both 15 leads a forward and a backward extrusion side from it extending hollow aprons with hub with respect to the raw part, so that a hollow axis parallel Inner ribs, which is obtained from a cylindrical intermediate product 62, movable extrusion die with extrusion shoulder which is H-shaped in the central longitudinal section. At Warmund consists of a fixed lower die that will extrude ribs 288 and 290 onto the Is constructed in several parts and an extrusion counter 20 pressed in opposite directions hollow punch comprises with extrusion shoulder in which the aprons 82 and 84 of the workpiece are formed. Ejector is arranged, with the counter punch Such an intermediate product is particularly for from a centered further processing to motor vehicle wheels forming the extrusion gap ^ arranged ring part is surrounded, which can be easily verdes below, however, for other purposes Extruding gap turn an extension compared to 25, for example for the production of belt ends Forms extrusion counter ram and also being disks or other end products. Example the two extrusion dies the counter-shape of the rib way, gears can be produced by have pen and are guided to one another. According to that ribs in the form of front teeth on the inner end Invention, such a press die is characterized by the side or outside of the hot-extruded hollow that the ring part for the simultaneous 30 aprons are formed.

Backward extrusion, as known per se, corresponds to the press die shown in the drawings

Correspondingly over the end faces of the extrusion counter-has a fixed main base plate 202 on

stem feed protrudes and intermediate plates 204 and 206 are fixed in the area of the

The extrusion gap is attached an upwardly conical by means of screws 208. On the plate

Has extension and that the ring part to the 35 206 is a fixed ring 212 by means of screws

To facilitate workpiece removal, they can be lifted 214, which are fastened in threaded bores 216 of the

is stored. Plate 206 are screwed in. The plate 204 is in

The invention will now be countersunk with reference to plate 202, as shown at 217.

Drawings on the basis of a preferred embodiment A vertically movable ring part 218 is by means of

In its details, for example, compressed air can be moved upwards, which through channels

wrote. In the drawings, 220, 222 and 224 are introduced into spaces 226 and 228

Fig. 1 can be a schematic central longitudinal section. By moving up this

In a preferred embodiment of the press die ring part 218, a return spring 231 is loaded,

kes according to the invention in a position in which down on disks 230 of rods

the movable extrusion ram is supported after completion 45 232, which in turn at 234 in the ring part

of its working stroke its lower limit position is screwed in,

has enough when fluid (e.g. air) is under pressure in

Fig. 2 is a part of the channels 220, 222 and 224 introduced on an enlarged scale

Section from Fig. 1 along the plane 9-9 in Fig. 4, the ring part 218 up to its upper movement

Fig. 3 in an even more enlarged scale 50 limit moved upwards, which by not common Partial section from FIG. 2, which the press showed suitable stops is intended, the mitenkenk shows in a working position in which the act on the disks 230, for example. The ring both The extrusion die and the ring part, the part 218, is in its lowermost shown in FIG starting to exert pressure on the workpiece, position returned by the springs 231 as soon as

F i g. 4 shows a partial section along the plane 10-10 in 55 the air pressure in channels 220, 222 and 224

F i g. 2, is being built.

F i g. 5 a partial section along the plane 11-11 in The ring part 218 is with a conical centering

F i g. 4, surface 236 equipped with a conical

6 shows a partial view of one of the surfaces 238 of the intermediate plate 206 shown in FIG Extrusion ram as an example can also be brought for the 60, whereby the ring part 218 zen-top view of the other extrusion die, triert and determined its lower limit of movement

Fig. 7 is an enlarged partial section from. A neoprene seal ring 240 resides in one

F i g. 2, groove extending around ring member 218

F i g. 8 one of the F i g. 7, and is also slidable on the inner surface of the which, however, the movable extrusion die in 65 ring 212 and seals against it. The ring partially in the retracted position and part 218 has a very slightly conical inner

FIG. 9 shows a partial section similar to FIG. 8, surface 242, which is the outer limit of movement

However, the press die according to the invention in and guide for the forward flow of the hollow

5 6

Apron 84 and the backward extrusion of the hollow chisel 264 is a similar extrusion shoulder 278

Apron 82 of the workpiece 62 forms. shaped. The extrusion counter punch 248 has

At the plates 206 and 204 an extrusion half of the extrusion shoulder 276 is at 280 a small

Counter punch 248 fastened by means of screws 250. larger diameter than the extrusion shoulder 276,

This extrusion counter ram 248 is with its un- 5 and the movable extrusion ram 264 has upper

lower end 252 countersunk into plate 204 so that half of the extrusion shoulder 278 has one at 282 in

he is centered by this. similarly reduced diameter. The GE-

An ejector rod 260 with an ejector cavity for the hollow skirts 280 and 282

head 262 is due to hydraulic pressure upwards so are recessed in such a way that during hot flow

movable to press the workpiece from the extrusion counter- io these hollow aprons as small as possible

stamp 248 to be able to take off. The ejector head presented and exposed surface of contact with the die

262 has the shape of an inverted truncated cone so that the friction of the metal is as low as possible

and has a flat top 265 with an indentation on the die walls,

recess 265 A , the latter for the plant according to the invention, the ring part 218 is longitudinal

Centering hub 34 of the blank is determined. 15 of its inner annular die wall 242 slightly

The movable extrusion die 264 is widened conically with the aid of a fitting, so that this inner wall

a movable plate 268 on a movable one upward in FIG. 7 shown, from the plane

upper press part 266 attached. The movable 242 / to the plane 242 K increasing diameter

Extrusion ram 264 is attached by means of screws 270. This will result in the ejection of the finished work-

the plate 268 attached. 20 pieces by lifting the ring part 218

Electric heating elements 258 and 274 are used for tert. The increase in diameter of the slightly conical

Heating of the two extrusion rams 248 and 264 inner wall 242 of the ring part 218 can be, for example

essentially to a temperature below the way between 242 / and 242.K 0.127 mm,

Preheating temperature of the workpiece, the one if the inner diameter of the ring part 218 about

must be sufficiently high to avoid cracks in the 35 30.5 cm and the axial distance between 242 / and

extruded hollow aprons and ribs of the work- 242 K is about 5 cm. The ring part 218 forms

To avoid the piece and to reduce the pressure- two annular die surfaces, the uniform

set, the distance around the extrusion shoulder 276 and 278 to carry out the extrusion process

ges is required, which on the other hand have enough and interact with it in such a way that

accordingly must be low in order to prevent the 30 that two opposing annular

Workpiece melts or recrystallizes, thereby forming die cavities which

loses its forgeability or causes it to occur with the formation of the hollow skirts 82 and 84. the

Gebungsringteil or the extrusion rams ver distances between the die wall 242 and the

welds. In the case of aluminum alloy, extrusion shoulders are 276 and 278 are at the opposite

this temperature is preferably 175 to 205 ° C. 35 currently the preferred embodiment of the invention

The movable plate 268 is provided with a see cylindrical substantially equal and give substantially guide ring 269, the cash to adjustable same wall thicknesses of the hollow aprons 82 and 84. Wear plates 269 ^ 4 is attached, which Tapered surfaces 242 M and 242 L (Fig. 7) abut against the ring 212 so that they center the extrusion die 264, which is provided above and below the die wall 242, with respect to the ring 40, avoiding contact with and thus friction with part 218. The upper position of the plate 268 corresponds to the hollow skirts 82 and 84. The tapered one is indicated schematically in Figure 1 of the drawings by area 242 M terminating at the top 286 of the ring by a dot-dash line 268 A. part 218. The tapered surface 242 L ends

When the movable extrusion ram 264 is raised on the inner cylindrical wall 284 of the ring, the preheated blank is placed on the 45 part 218, which in turn has a larger penetration inside the vertically movable knife, to abut against and thus a Rei-ring part 218 arranged extrusion counter ram with the hollow skirt 84 to avoid.
248 is placed and the hub 34 bears against the ribs or the like. At this point in time, hollow aprons 82 and 84 form that the walls of the ring part 218 are spared in its lowermost one shown in FIG. 1 in 50 press die according to the invention according to solid lines. In the currently preferred off position, the extrusion blanks are closely spaced around the circumference of the guide form of the invention, as can also be seen from FIG. 3 of drawing shoulders 276 and 278 at 292 and 294 (FIG. 2 openings. to 6) to form ribs 288 and 290 on the

The movable extrusion die 264 moves 55 hollow skirts 82 and 84 provided with grooves, which then down into abutment against the blank 56 along the inner sides of the hollow to be formed (Fig. 3), whereupon the metal skirt radially outward 82 and 84 and extend parallel to their central direction towards the delimiting slightly conical axis. The walls 292 Λ and 294 Λ of the surface 242 of the ring part 218 begins to flow and the die grooves 292 and 294 adjacent flow the actual extrusion process on the rounded so press rams 248 and 264 again have the form th shoulders 40 with the formation of the oppositely widened grooves, which are at a distance from the hollow aprons 84 and 82 of the working ribs, which are to be extruded, so that the piece begins. These hollow aprons consist of hot extrusion of the same only a small amount of space with the intermediate floor 80, which is created by exercise with them.
the non-flowing metal of the blank is formed. 85 Figs. 7, 8 and 9 show how the finished work

At the top of the extrusion counter punch 248 piece 62 from the press die 60 is ejected.

an annular extrusion shoulder 276 is formed, FIG. 7 shows the movable extrusion die

and at the bottom of the movable extrusion 264 at the bottom of its stroke. F i g. 8 shows the

Claims (1)

movable extrusion ram 264 in upward movement, while the ring part 218 and the extrusion counter ram 248 remain stationary. The workpiece 62 also remains standing as long as the outer surface 276Λ of the extrusion shoulder 276 of the stationary extrusion counter punch 248 together with the opposite surface 242 of the zone 242 T exerts a slightly stronger pressure on the hollow skirt 84 than the pressure between the outer surface 278 v4 of the movable one Extrusion die 264 and the upwardly widening surface 242 in the zone 242 if (FIG. 7) is exerted on the hollow skirt 82. The outward expansion at 242Jf allows the movable extrusion ram 264 to move upward with decreasing pressure, while at 276A there is a tendency to increase the pressure. Any tendency of the movable extrusion ram 264 to pull the hollow skirt 82 upward with it has the consequence that the movable ring part 218 also tends to move with the workpiece. As a result of the tapering of the die wall at 242 T, there is a tendency to press the workpiece more strongly against the outer surface 276.4 of the extrusion shoulder 276 of the stationary extrusion article 248. This helps prevent the movable extrusion ram 264 from pulling the workpiece upward with it. Once the movable extrusion die 264 moves up slightly, the upward tension acting on the upper hollow skirt 82 compared to the increasing pressure effect on the lower hollow skirt 84 becoming weaker and weaker. The movable extrusion die 264 can therefore can be easily pulled upward, as indicated in Fig. 8, without the workpiece 62 significantly is pulled up. Finally, the movable extrusion die 264 can go all the way up be pulled out without the workpiece being taken and without it being deformed in the process will. F i g. 9 shows the ring part 218 during its upward movement, which then begins when the movable Extrusion ram 264 has been moved sufficiently far up and completely from the hollow skirt 82 was released. The ring member 218 is moved upward by pressurized air which is passed through the Channel 220 is initiated (Fig. 1). This compressed air is distributed among the undersides 226 and 228 of the Ring part 218 and under the exposed lower surfaces of the intermediate floor 80 of the workpiece 62, whereby it is prevented by the seal 240 from escaping. The ring part 218 is therefore after pressed up, taking the workpiece 62 up with it, as indicated in Fig. 9, wherein the path of upward movement of the ring member 218 can be approximately 15 cm. When the ring member 218 is moved upward by stops not shown in the drawings the rod 232 (Fig. 1) comes to a standstill, the workpiece 62 is by the compressed air further upwards, this movement being caused by the ejector head, which is also moving upwards 262 is supported. The ring member 218 is then supported by the springs 231 cooperating with the rods 232 in FIG returned to its lower position, while the movable extrusion die 264 and the ejector head 262 remain in their upper positions. As a result, the workpiece 62 comes completely off the ring part 218 free. Now the ejector head 262 is lowered while the movable extrusion die 264 is still remains in its upper position. The now freely resting on the top of the ring part 218 The workpiece can then be removed from the press die 60, so that another heated blank placed on the lowered ejector head 262 and the stationary extrusion die 248 can be, whereupon the sequence described above is repeated. Claim: Heatable press die for hot extrusion production of hollow cylindrical parts for further processing into wheel rims from a preformed raw part made of wrought alloy, in particular aluminum, with an approximately central intermediate base and hollow aprons extending on both sides with axially parallel inner ribs, the press die consisting of a movable extrusion die with an extrusion shoulder and a fixed lower die. which is constructed in several parts and comprises an extrusion counter ram with extrusion shoulder, in which the ejector is arranged, and wherein the counter ram is surrounded by a centered annular part forming the extrusion gap, which below the extrusion gap forms an extension compared to the extrusion counter ram, furthermore the two extrusion rams have the opposite shape of the ribs and are guided to one another, characterized in that the ring part (218) for the simultaneous backward extrusion, as known per se, correspondingly over it protrudes the end faces of the extrusion counter ram (248) and has an upwardly conical widening (242 W) in the area of the extrusion gap that is being formed and that the ring part (218) can be lifted to facilitate the removal of the workpiece. Considered publications:
German Patent No. 709 573;
French Patent No. 1,278,208;
"Der Maschinenbau" magazine, issue 7, 1960, P. 198. 1 sheet of drawings