DE1062201B - Mechanical press for cold extrusion of metal objects - Google Patents

Description

GERMAN

Cold extrusion is generally useful when processing relatively soft metals, ζ. Β. Aluminum, brass or the like, with known mechanical presses no particular difficulties Cold extrusion of harder metals, e.g. B. of steel, on the other hand, difficulties arise when a \ conservative A high degree of deformation is required, which means that the press parts and tools are subject to high pressures or Subject to pressure surges.

This is why attempts have been made to address the problem of cold extrusion of steel or other harder metals solve in a special way. So one has z. B. for cold extrusion of gears made of steel a mechanical Press created, in which between the press ram and tool carrier an elastic cushion in Is arranged in the form of a helical spring, via which the exerted by the press on the workpiece Pressure is initially increased gradually. When the spring coils run up against each other, a Impact generated by which the flow process is to be initiated. Nevertheless, the design must take place in several work processes, with the workpiece being annealed after each work process must become.

It is also a mechanical press for cold extrusion of metals is known in which a between Press ram and tool provided elastic intermediate member when transferring the full, for pressing necessary force from the working pressure becoming effective and this energy as it progresses Returns the cold flow process to the workpiece. This has already made it possible to create workpieces made of steel in a cold extrusion process in one operation.

The aim of the invention is to improve such mechanical presses for cold extrusion so that Workpieces made of hard metals in one operation with a higher degree of deformation than before or Complicated workpieces with a high degree of deformation completed in one pressing process can be. Here, the press should only be good when it comes to achieving high levels of accuracy in the workpiece forms be exposed to wearable stresses.

Starting from a mechanical press for cold extrusion of Meta 11 against st to the using an elastic cushion inserted between the press ram and the tool carrier, after the compression of which under the deformation resistance of the press ram occurs positively on the tool carrier and continues its pressing path, the invention consists in that for the positive connection of the press ram and tool carrier an adjustable stop is provided, depending on the shape and material of the workpiece, the mechanical press for cold extrusion
of metal objects

Applicant:

Marguerite-Elisa Chappuis, née Pretre,
Tüla-Marguerite Chappuis,

Simone Chappuis

and Jacques-Albert Chappuis,

Neuchätel (Switzerland)

Representative: Dipl.-Ing. C, Wallach, patent attorney,
Munich 2, Kaun'ngerstr. 8th

John Albert Chappuis t, Neuchâtel (Switzerland),
has been named as the inventor

Flow process to be able to determine the optimal preload of the cushion and the point in time at which the flow process is to be initiated.

The invention is based on the knowledge that it is crucial for proper flow of the metal The meaning is at what point in time the impact caused by positive locking between the tool and Press ram comes about, is exercised. Because the amount of preload and the time of the The transition from the pre-compression and final compression pressure can be precisely determined, can in the case of the device according to the invention easy flow of the material can be achieved with moderate exertion of force. Both a Surprisingly, falling below and exceeding the optimal preload leads to too much worse results, only relatively small deformations can be obtained. Namely takes place the initiation of the strike too early, then the device works like a coin press, and the Preload is not effective in the supporting sense for the cold extrusion process; for a Proper flow requires that the metal is already in a certain way due to the preload being prepared. If, on the other hand, the impact occurs too late, i.e. only when the preload is already flowing of the metal in the die, then the metal may harden, and the desired degree of deformation cannot be reached either.

909 579/176

3 4

An expedient embodiment of the invention consists of springs in five facing groups of each it says that the stop is a nut that provide on two springs (as shown),

the piston-like guided in the press ram and against In the example shown are the selected springs the resilient cushion supported tool carrier exposed to an output voltage that is present 5 is opposite to the end face of the press ram when the press is running empty and the nut 5 is on

is screwable. Plunger 1 is applied. It is often desirable to use this starting point

Furthermore, the invention is preferably to be significantly increased in terms of expression, which can be achieved by robbing

stalten that the rest tension of the elastic cushion of the nut 5 can be achieved,

by means of a button on the back of the press ram - The springs are strong enough, among other things, to

striking nut is adjustable, which can be achieved on an io punching of the workpiece χ from the band X

Piston rod-like extension of the tool carrier possible. The punched workpiece is inserted into the

sits. The die is pushed in, where the pressing process takes place

The elastic cushion can be made in practice in accordance with Fig. 2 from the moment

In such cases, spring plates are often used, in which the patrix 8 strikes the workpiece χ

packages exist. 15 and presses it against the bottom piece 11.

In the following description, the invention is based on While the press ram is then lowered,

liand of drawings explained in more detail. In them _t ( _cn the springs are more and more compressed, and

shows the workpiece is subject to elastic pressure,

Flg. 1 shows a longitudinal section through the head of the press which grows until approximately the position shown in FIG.

and through the tools at the moment when it is sufficient.

punching the blank, as can be seen, a tiny part of the

Fig. 2 penetrated the same parts before the start of the press material in the axial hole 9, where he

1 organges, forming a small protrusion y , practically of one

Fig. 3 shows the same parts when the workpiece is already of the order of magnitude, for example, when minting coins.

something has been deformed, 25 comes.

Fig. 4 shows the same parts during the flow process. Under the action of the cushion is the material

... inges, squeezed to a limit, over

FIG. 5 shows the same parts after flow has taken place, which they also flow plastically after a short time

process when the patrix recedes, begins.

6 shows a diagram on which the movement 30 is just meeting at this moment

of the press ram. that of the patrix and the ram of the press, which is further lowered than in FIG. 3, onto the

speaking shortening of the compressing nut 7, as shown in 13 in Fig. 3, so that

elastic intermediate links with reference to the time patrix and press ram are now positively

are made. are connected to each other and the patrix inevitably

FIGS. 7 and 8 are two of the Fig. 4 similar 35 _w ith the plunger instant sharing-eht. The tool material will

Axial sections, which on a slightly larger scale are suddenly compressed so much that it

two of the various possible forms of accelerating begins to flow by passing through the

Show matrix and patrix. Opening 9 escapes and the extension s according to FIG. 4

According to Fig. 1, the press in question has forms. This flow takes place in the cold state, a plunger 1 with pin 2, on which the ₄ “You can also say that the process has two cranks or an eccentric (not shown) steps, namely one, during which a pre-connected connecting rods 3 work. Inside this pressure is exerted, and one during which the plunger is a cylindrical space in whose flow takes place. Although the first stage is only about a bolt 4, which can be moved axially and lasts for a few hundredths of a second, one can be held back by the nut 5 at the top. At 45 g _{sa e,} n that it is relatively longer than the lower end of which is a threaded, reciprocating second.

like tool carrier 6 with a nut 7 indicated at a given working speed of the press

Bracht, which can be adjusted in height by turning. can increase the duration of the first stage by choosing one

The device shown processed cylindrical specific path for the compression of the

Blanks x, which are made of a metal tape X, which are determined on the ₅₀ pillow during the duration of the

Die 10 is to be cut out second stage of the characteristics of the chosen

The patrix 8 is used to punch out the workpieces is dependent on the press. But both are of the thickness of the

and \ ^f form the same. Depending on the workpiece as well as on the quality and

In the present example it is a question of the amount of metal to be deformed,

a workpiece in the form of a circular disc 55 The lower dead center of the male mold is set so that

to get, from the middle of which a pin rises, that hereby the thickness of the finished workpiece

the length of which remains a multiple of the slice thickness. This can be done by using the

üagt For this purpose, the male part 8 has an axial male part on the tool holder 6 accordingly

Hole 9. or the height of the die changes.

In the cylindrical cavity of the plunger between 60 FIG. 5 shows the after pressing process

the tool carrier 6 and a base is the relaxed spring 12 when the plunger 1 is

arranged elastic cushion, which has lifted from plate here, and the nut S of the shaft 4 on the

springs 12, which surround the bolt 4 and abut an upper surface of the head. It pulls on

since ;, on the tool carrier 6, on the other hand on the mentioned also the patrix back.

Touch the floor. Of course, the plates are 65 Fig. 6 illustrates in a curve the ge

i'edern only given as an example; because the processes described can

lift other resilient members are used. The sine curve 14 corresponds to the movement of the itself

The way how to lower the disc springs and then raise the plunger, if it z. B.

composed, allowed, very different elasticity ^ .- set in motion with the help of a crankshaft

To acquire characteristics. One can, for example, turn ten to 70, a movement that the male part 8 performs

Claims (1)

3 6 when it is permanently positively engaged with the plunger pressure. By screwing the nut 7 to would be connected. to stop with head 1, however, one could The curve 15, on the other hand, corresponds to that caused by the metal by 1.5 mm in the male Patrix 8 actually covered. This drives opening up. up to point 16 with the plunger. Then she hits 5 with double the number of springs and 4.4 mm elastic on the workpiece χ (the punching out of this latter stic compression could under the same is not taken into account here), the metal is stopped and conditions are moved 3.2 mm deep into the male part then practically no longer while the opening is being driven in. Tension of the springs according to curve 17 to- With three times more springs, which one by 6.6 mm takes. io, came out 4.1 mm. The points 18 and 19 correspond to the sudden when you stare the feathers together by 8.8 mm Connection of the male part to the ram, d. H. pressed, the appendix was only 3.1 mm long, In 18, as the starting point for a sinusoidal loading, the springs became 25% more convergent of the patrix and one in 19 as the starting point, the result was only 2.6 mm. remaining maximum tension of the springs. 15 The duration of the first stage, i.e. H. of the elastic The more of these curves understood. Pressure varied between _^5/100 and ¹⁷ V ₁₀₀ seconds. In the same way, as described, can also be used during the time during which the patrix is differently profiled workpieces are produced. moved rigidly with the plunger, was much shorter, e.g. B. So shows z. As the Fig. 7 the manufacture of a tool ¹ Z ^_100-5 / ₁₀₀ seconds. So there is an optimal one Piece, which on one side has several values for the duration and level of the elastic pressure, sentences 2 ¹ , z ² and an extension s ³ on which the greatest possible flow of the metal gc- other side. The bottom piece has dismantled one for this. This value depends, among other things, on the speaking hole. Hardness of the metal being processed, the size of the Fig. 8 shows the production of a workpiece, piece, the amount of metal to be expelled, the with a circular rib s ⁴ on one side 25 type of springs etc. and can be given under and an extension 2 ⁵ in the middle of the other side. Requirements are determined. A corresponding one The patrix has a ring-shaped recess for this purpose, but it has not yet been established. on. Since the position of nut 7 on the work It goes without saying that one z. B. It is also possible to carry a lot of things, the moment in which one Can press angular workpieces and that the flowing 30 pressed over from the elastic pressure to the rigid pressure Continuations also angular profiles open up, to be determined at will, it is easily possible, can point. the two stages of work in the most favorable way In the case of relatively soft metals, this has to be coordinated. Cold flow in without difficulty. If you process what the compressive forces in question however steel, so the lengthening of the pressing process 35 is concerned, it could be determined that for mild steel important, d. H. the deceleration of the speed with a hardness of 100 to 115 Brinell and one of the tool from the moment in which it has the necessary elastic ^{with a surface area of 100 to 110 mm 2} comes into contact with the workpiece. Maximum pressure was about 17 t, ie 200 kg / mm ² . The first stage of work is supposed to last the longer, the percentage of the metal that passes through KaItje more the final shape of the 40 extrusion to be produced with the right choice of ratios Workpiece differs from that of the blank that the blank can drive out is proportionate d. that is, in this case it requires the achievement of the large. So you can z. B. with mild steel approx. 28% Drive more of the metal in a pin, which determines the flow process Time. In contrast, the second stage, i.e. the flow diameter, must be approximately 22% of the workpiece throughput even, under the limit pressure reached, corresponds very much to 45 meters. It even managed to take place at river suddenly. st aiii up to 60% of the volume of the blank to drain In the example described, the pressure increases because
the interposed springs more and more be squeezed. During this time, the claims.
a few hundredths! Takes seconds, the blank 50 1st mechanical press for cold extrusion is forced to completely fill the space available to it metal objects with a press ram between. Immediately afterwards and the elastic cushion that is effective for the tool carrier, as soon as the optimum limit pressure is reached, it begins to flow under the metal after it has been compressed, and from this moment on the mold resistance of the press ram is no longer necessary Tool carrier meets and limit patrix. continues its pressing path, characterized in that Tests on a crank press with 100 um- that to produce the form fit of press rotations per minute and a stroke of 60 mm with plunger (1) and tool carrier (6) one after the other Mild steel blanks of a diameter of the most favorable pressing pressure and timing for the on-11.5 mm and a thickness of 3 mm, with a patrix, 60 line of the flow process adjustable stop which had a hole whose diameter is about (7). 22% of the blank diameter. have the following 2nd press according to claim 1, characterized result: shows that the stop is a nut (7) that Without a spring cushion, the metal of the blank on the piston-like in the press ram (1) was not more than 0.3 mm into the patrix hole and pressed against the elastic cushion (12). With the aid of eight disc springs, the supported tool carrier (6) opposite which, distributed in four groups of two mutually pulling end faces of the press ram, can be screwed.
returned springs, the result was the same, insofar as the 3rd press according to claims 1 and 2, was acted briefly and the springs were only 2.2 mm thick, that the rest tension of the elastic pressed together, ie with purely elastic Cushion (12) by means of a on the back of the 7 8 Press ram (1) abutment nut (5) - "workshop books", booklet 58, Kaessberg, Hugo: is adjustable, which is based on a piston rod-like "drop forging of steel", Part II, 2nd edition, Extension of the tool carrier sits. Springer-Verlag, Berlin / Göttingen / Heidclberg, 1951, P. 39; Considered publications: 5 "Werkstattstechnik und Maschinenbau", 40th year - German patent specification No. 847 834; gang, No. 9, September 1950, p. 333;
British Patent No. 662,705; Wire, Volume 2, September 1951, No. 9, U.S. Patent No. 2,112,284; P. 240. 1 sheet of drawings i 909 579/176 7 59