DE2047931A1 - Method and device for deformation of materials with the aid of a fluidic pressure medium - Google Patents

Description

Patent attorney
Oipl.-lng, Walter Jackisch 2047931

7 Stimnrt N, Menzelstrasse 40

~ 2 a Sep. 1970 Western Electric Company Inc * A 31 921 fd

Method and device for deforming materials with the aid of a fluidic Pressure medium.

The invention relates to a method for deforming materials with the aid of a fluidic pressure medium, wherein a material is pressurized and subjected to an extrusion process to shape a product The subject of the invention also includes a device for the extrusion of materials with the help of a fluidic pressure medium via a passage, which in a 3 flow control element of a Shaping means is formed.

Be one of the earliest known extrusion or

Extrusion process was an ingot-shaped blank M

inserted into a receptacle, the inner diameter of which is essentially equal to the outer diameter Was blank and which flowed into a mold through which the blank material in the course of a corresponding Deformation or reshaping to the desired, for example wire-shaped product pressed through by means of an advancing ram became. A deformation within the pressurized Blank is in such a process

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due to the support of the blank by the inner surface excluded from inclusion. The one required to press or extrude the blank material Determine the feed force and its effect in such a procedure according to the following criteria:

1) The ideal value of the work of deformation per unit volume of the material required to transform the blank into the desired product (work with homogeneous deformation). This quantity is referred to as P ^.

W 2) The energy per unit volume to be used for the sudden change in direction of the material flow of the deforming blank, designated as P, at the beginning of the deformation and when it arrives at the exit of the press mold (excess energy).

5) The energy per unit volume required to apply the surface friction between the blank and the die, denoted as P _{f (i}

4) The energy per volume unit required to overcome the surface friction between the blank and the holder, referred to as P-.

W An improvement of this method was the development of the hydrostatic impact extrusion Here, the total Rohlingaoberflache with exception is that in the area of the mold with a pressure medium, ira general a DruckflüJägkeit, acted upon, and thereby progressively pressed by the press mold, wherein the surface of Rohlln; s. from the inner surface of a receptacle receiving it and the pressure fluid through this fluid

ΙΟί-818 / m *

is separated and therefore no surface friction in this area with a corresponding energy consumption can occur. (see Canadian Patent 476.793 * 3rid? * Man) .-

The expenditure of force and energy is still undesirably high in the last-mentioned method, despite the fact that the surface friction between the blank and the pressure vessel does not include _{the remaining components P p and P ^^.} Attempts have been made to further reduce the remaining expenditure of force and energy, but without success.

Except for the undesirably high driving force Difficulties in terms of product quality arise in the known extrusion processes. At the Hydrostatic extrusion are e.g. the side surfaces and the side facing away from the die of a limited blank uniformly under pressure set. In some cases, additional longitudinal forces were applied to the exiting Tensile forces acting on the product or compressive forces acting on the blank by which the blank material Longitudinal component of the driving force through the die

to increase hydrostatic pressure. Those with the well-known hydrostatic extrusion processes The products achieved are not yet satisfactory for 3 different reasons. In extrusion For example, undesirable irregularities often arise in the form of a disk or ring formation with deviations through the hole and poor surface quality. The irregularity of the physical Properties of the product also play a role here a higher probability to after that

1ÖÖ818 / 129S

Extrusion occurring bricks.

In some cases there may be a non-uniformity of the external shape or the physical properties for example in the manufacture of rods or certain types of wire, in many others In some cases, however, such irregularities are not permitted. This applies to manufacturing, for example of wires, especially those of small diameter, for electrical conduction purposes in which the uniformity of the wire diameter and the grain structure of the material is of great importance.

The object of the invention is to create an extrusion process, which differs from the known method by overcoming the aforementioned difficulties both in terms of the amount of driving forces as well as in terms of the uneven ones Shaping and the uneven distribution of the physical properties in the product. The inventive solution to this problem characterizes In a method of the type mentioned at the outset, this is mainly due to the fact that the material is guided within a controlled flow of pressure medium and that the deformation is caused by the action of the pressure medium is brought about on the material, which is also under pressure.

Oem according to a further development of the procedure according to Invention can be radially and radially in the material to be deformed by applying suitable pressure Axial stresses are generated in such a way that the amount of the radial stresses is increased

.109818 / 1295 bath c-l

exceed the axial stresses by at least the yield stress of the material while the material undergoes Forming into the desired product within a controlled flow of pressure medium that provides the required Applies deformation pressures by a corresponding Flow or extrusion mold is performed.

According to another embodiment of the method according to the invention, the pressurization of the Material changes depending on the changes in flow resistance that occur in such a way that a predetermined deformation speed of the material or a corresponding exit speed of the Product is maintained. Changes in properties of the within the pressure medium flow Deforming material can in the inventive method by quickly adapting the Extrusion effecting pressures taken into account and so irregularities in terms of shape and Properties of the product are avoided. The deformation of the material with the help of a pressure medium flow also switches off any surface friction between the blank and the pressure vessel and the mold in the area of the deformation zone, resulting in a A corresponding reduction in the drive power results, so the invention is a considerable advance both in the execution of the procedure as well as in the Product quality erfeit, especially through compliance with a specified deformation rate and the achievement of a high degree of conformity the physical properties within of the deformed material.

1098 1.8 / 129 p

It was also found that the relationship between Radial and axial stresses due to strain hardening (commonly referred to as "work hardening") a maximum of the pressure acting on the surface of the deforming material requires a point that is downstream of that of the deformation start, i.e. in the direction of passage is offset. With such materials, the deformation takes place both upstream and also downstream of the point of highest pressure.

Bf-> i also belonging to the subject matter of the invention Use of an advancing into a closed amount of pressure medium or into a pressure fluid chamber Flow control element, on whose control surface a deforming pressure medium flow is generated, the point of the pressure maximum is at (seen in the direction of flow of the material) front edge of the flow control element. When processing materials that are subject to deformation hardening show and in which the point of the pressure maximum in an area downstream of Deformation start is shifted, the deformation start occurs before and thus outside of the flow Control element. Although this can generally be allowed, it does not result in this way Optimal form-fit control of the deformation process, as they are completely within the flow control element when the deformation takes place would be possible despite deformation hardening.

The object of the invention is therefore also to create a method and an associated device for pressure fluid flow extrusion (hereinafter also referred to as "form-fitting flow extrusion ¹¹ ), wherein the deformation of the material can be carried out completely within a flow control element of the type mentioned. This can be according to the invention achieve that to generate a pressure medium flow lä% s the control surface in the passage of the flow control element, pressure medium is injected in the area between the ends of this passage , for the extrusion of the material required pressure takes place.

Another object of the invention is to create an extrusion and in particular an extrusion device, by means of which the according to the invention Process can be carried out advantageously. The invention The solution to this problem is characterized by a device of the type mentioned at the beginning mainly by the fact that the surface of the Passage forms a control surface for guiding a pressure medium flow and that drive means for Generating a relative speed between the material and the shaping means arranged in the way are that the pressure medium forming a controlled flow under pressure into the passage is introduced and the material passes through the passage within the thus generated pressure medium flow. A further development of the invention, in particular

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The above-explained conditions for materials with Verforraungsverfestigun3 takes into account, is characterized by the fact that a device for injecting pressure medium is provided between the ends of the passage and for generating a controlled pressure medium tr otnes.

In an advantageous embodiment of one according to the invention Flow control element is a passage extending in the feed direction within the main body of this control element provided, at least part of the surface of this passage as a control surface for influencing of the pressure medium flow and a special one in the area between the ends of the passage DruckmittelzufUhrung is provided.

Further features and advantages of the invention emerge from the following description of exemplary embodiments of the invention with reference to the drawings. Herein shows

Fig. 1 is a longitudinal section of a hydrostatic

Extrusion equipment of known type,

Fig. 2 shows the course of the pressing pressure a flow process in the device according to FIG. 1 in diagram form About the increasing total volume of the extruded product,

5 shows the longitudinal section of an inventive Extrusion device,

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Fig. 4- the schematic longitudinal section of an ingot-shaped blank in a processing state within the device according to FIG. 3 with a schematic vector illustration the pressures and forces acting on the blank or the stresses existing in the material,

Fig. 5 is a diagram of the radial and axial stresses in the »Verkptoff over the feed path one of the deforming pressure (| medium flow generating flow control element es,

Fig. ^F i a partial longitudinal section of the device according to the invention with the deformation zone of the bulb and

7 shows another embodiment of one according to the invention Extrusion device in longitudinal section.

Furthermore shows

Fig. R shows the dependency of the closing pressure within the pressure medium and that the flow strength of the material from Blank radius in diagram form in the case of the inventive Deformation of the material,

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1ÖÖ818 / 129Ö

- 1ο -

Pig. 9 and Pig. 10

each a partial longitudinal section of another embodiment of a erfindungsgeraässen Extrusion equipment on a larger scale,

Pig. 11 the mutual assignment of the partial longitudinal sections according to FIGS. 9 and 10,

Pig. 12 shows a partial longitudinal section of the extrusion device according to FIG. 10, but in a working state before the complete deformation of the Amount of material of the blank, and

Pi/;. 13 is a partial longitudinal section of the fluid control element from the device according to FIGS. 9 and 10 or according to FIG. 12, but on a larger scale.

First of all, reference is made to the representation of a known hydrostatic extrusion device according to FIG. 1 Reference * This device, designated as a whole by 11, comprises a pressure vessel 12 with a closed End 13 and opposite open end, in which is an extrusion mold 14 (hereinafter referred to as “compression mold **” for short) with a mold opening 16 forming shaped ring 17 is used. A longitudinal central bore is located in the support body 15 of the compression mold 14 18 provided for the exit of the shaped product 20, in the example wire or rod-shaped.

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During operation of the device 11 according to FIG. 1, a bar-shaped blank I9 is inserted into the vessel 12 filled with a pressure fluid via a feed line 21 with a control valve 22. The pressure within the vessel is then increased to a value dependent on the material of the blank, at which the deformation and flow of the blank material begins through the mold opening 16 into the bore. During the deformation, the blank I9 is in contact with the mold ring 17 *, the pressure acting on the blunt end 31 of the blank doing the work of homogeneous deformation P _h , _{the excess energy P r} and <| the energy to overcome the frictional force between blank and die P _fd must apply. As already explained in the introduction, this results in an undesirably high application of pressure to the blank, which is necessary for deformation. Of the phenomena that adversely affect the product quality, the formation of annular circumferential edges 23 at certain distances from one another on the emerging product 20 is indicated in the example. An unpredictable and non-uniform distribution of the physical properties, for example with regard to work hardening and grain structure, also occur.

It was found that form disruptions like the indicated formation of annular circumferential edges on the product at least partially due to the frictional forces due to the physical contact of the blank material with the die surface during extrusion originate. The deforming material tends to slide through in a jerky, settling manner along the die surface,

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but not to a molding process with an essentially constant deformation rate * such as it would be desirable to produce a uniform product. The abrasive sliding of the As studies have shown, the material can be traced back to one or both of the following causes:

1) Periodic changes in friction between The blank and the die surface influenced the flow rate of the material;

2) a non-uniform distribution of physical Properties of the blank material, which can be found in a) over the length of the exiting material strand Difference in the course of the deformation or Pließprees resistance can make noticeable.

The periodic changes in the flow speed of the material can be explained by the jerky overcoming of the static friction between the material and the press-molded surface with a subsequent overshooting of the outlet speed and the following slowing down and approaching or transition to friction Static Friction Without Relativgesoiwlndigkeit initially a higher pressure is required than to maintain a flow process with a constant product discharge resistance. So if the supply of pressure medium in the outlet 12 takes place essentially at a constant rate of flow, the pressure initially increases, since there is no flow with the emergence of material until the friction between the material and the mold surface is overwhelmed After a corresponding increase in pressure, the

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Flow process «where the effective friction type is shown Overcoming the static friction drops and thus a There is excess pressing pressure, which is reflected in the above-mentioned overshooting of the flow velocity Expressed beyond the stationary value. The other * The result is a renewed drop in the pressing pressure below that required for a stationary flow process Value with subsequent slowing down of the emerging product, possibly up to the renewed formation of a Static friction or an adhesive friction. Eb results Thus, under certain circumstances, a non-decaying or only slowly decaying oscillation process, as shown in Fig. 2 for the pressing pressure: in the pressure vessel above the product volume that has escaped j

is shown. This representation practically under- ™

The conditions sought shows a steady oscillation of the pressing pressure between the limit values Λ and C around the mean value B corresponding to a steady flow process.

Non-uniformities in the physical properties of the material being processed, which result in changes the flow resistance have similar consequences like the friction between the material and the die surface. When a section of material occurs higher flow resistance in the deformation zone

The plating process is carried out within the mold. J

slowly, so that the pressing pressure with sustained Pressure medium supply as a result of decreasing volume outflow increases. After the exit of the materia section with increased flow resistance there is therefore an excessive one Pressure, which in turn causes the flow velocity to exceed the steady-state value hinais with a corresponding oscillation process. Here, however, is with a stronger one Attenuation of these vibrations to be expected,

1Ö9818 / 129S

because points of increased flow resistance occur in the material at irregular intervals.

Except for a lack of uniform shape have the changes of the flow "or exit" speed also result in other disadvantages. A certain flow velocity arises e.g. an associated working temperature within the Deformation zone. This temperature is subject to various influencing factors such as the ambient temperature, in many cases room temperature «the amount of heat generated by the deformation, the friction

™ between the material and the mold, the thermal conductivity the mold and the pressure vessel and the like. The ambient temperature can be viewed as constant and not taken into account in the present case stay. With increasing flight or deformation speed, the increase due to deformation and Refcung amount of heat generated and thus the temperature at. Conversely, the temperature in the deformation zone increases with decreasing flow velocity away. Since “the speed of the occurrence of the Deformation «solidification changes with temperature, so the degree of this solidification depends on the flow

£ speed of the material dependent. Changes of the last mentioned oroses therefore do not have only directly corresponding irregularities of the physical properties of the product result, but also cause over the corresponding Flieöwlderstand des changes subject to changes Material once again increases the non-uniformity.

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1 0 9818/12 9 p

The aforementioned disadvantages are due to the invention Process in its various embodiments or with the help of the devices according to the invention overcome, as can be seen from the following explanation.

3 comprises a pressure vessel 51 with a bore closed at one end 53. At the closed end, the pressure vessel is connected to a base 54. A cylindrical punch 58 is inserted into the bore 52 which, according to the arrow 60, is inserted into the pressure vessel. conversely, M can be withdrawn from this, with the help of a press, not shown, or the like ..

A flow control element 62 which is coaxial with the latter and has a control surface 63 is screwed to the punch 58. The control element 62 forms with the bore 52 a blank 65 in the form of a bar Chamber 64. The control surface 63 forms with a coaxial bore 66 of the control element 62 a Passage 67, the bore 52 of the pressure vessel connects to a coaxial bore 68 of the punch 58. The limited by the control surface 63 Section of the passage 67 defines a deformation zone 69, within which the extrusion process with Reshaping of the raw material into the desired product, in the example a wire 74, take place

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10981 8 / 129.6

The outer surface of the control element 62 is reset and forms with the adjacent portion of the punch 58 an annular groove for receiving a High-pressure seal 71. The latter comprises a sealing ring 72 with a cup-shaped cross section and a sealing ring For example, from Berylllumkupfer existing support ring 73. Other suitable high pressure seals can also be considered here.

The shaping of the blank 65 into the wire 7 ^ takes place in the device according to the invention during the passage of the workpiece via the passage 6f within a pressure fluid flow. It is essential that the material of the blank does not come into contact with the control element 62 at any time, since the pressure flow keeps the material surface at a distance from the control surface 63 and thus prevents any frictional forces as a result of direct surface contact between the plague bodies involved. Nevertheless, it should be noted that the pressure fluid flow in the passage 67 between the blank material and the control element is not a mere film of lubricant. The Druckflüs ^ gkeitsströmung, generally a m according to the invention the pressure medium flow used, but rather provides an active element of the shaping means is, which generates the force acting on the blank material deformation pressure within the deformation zone.

In the operation of the device 50 according to Pig. there are three main phases to be distinguished, namely, initial stage, continuous extrusion operation and final phase. In the first phase

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the blank to be processed is placed in the chamber previously filled with a suitable pressure fluid 64 used. The stamp 5Ö is then added the control element 62 is introduced into the bore 52 or the chamber 64 and advanced, with the flow of pressurized fluid via the control element 62 with the corresponding pressurization of the blank head results. The axial component of the resulting Force is applied to the foot end 70 of the blank within the chamber 64 transferred and received here by the pressure fluid. As explained in more detail below the pressure on the foot end 70 of the blank will rise more slowly than that on the head end of the blank acting pressure, resulting in a correspondingly non-uniform pressure distribution with corresponding stresses result within the blank material. With increasing pressures, the difference between them and the Stress difference to the latter until the yield stress of the blank material has reached and an equilibrium flow state is established.

This equilibrium is maintained during the extrusion process in operation. The designation ^w equilibrium flow state ^{w is} determined in the present context by the following criteria after the initial phase of the flow process:

a) A flow control element 62 is pushed into the chamber 64 at a constant speed,

b) a controlled DruckmitteIstrom passes through the Pass this control and

c) are the fluid pressures acting in the system of sufficient size to be within the

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1 0 98 1 8/1 2 9 p

Blank material to generate the stresses required for deformation, this deformation of the Blank to the product takes place according to a predetermined exit speed.

In the example, the wire 74 leaves the one according to the invention Extrusion device through channels 67 and 68.

After processing the amount of material in the blank, the final phase of the work process begins. Of the The punch 58 is withdrawn from the chamber 64 while the pressure is reduced. An undeformed remainder of the Blank can be severed from the end of wire 74 and removed from chamber 64. However, it is basically quite possible «to transform the total amount of the blank material into the desired product. When the chamber ö4 is free, a new work process can immediately be started by filling it with pressure fluid and inserting a new blank into the pressure vessel be initiated.

The method of operation is explained in more detail below.

Castor oil, for example, can be considered as the pressure fluid that is filled in when the chamber 64 is exposed. The blank is inserted into this chamber in such a way that its puss end 70 is arranged at a distance from the closed end 53 of the printing device 51. This is made possible by the fact that the diameter of the blank diameter is only slightly weaker than the diameter of the bore 52, so that there is a very narrow gap J6 between the circumference of the blank and the pressure vessel. This gap creates a high flow resistance for the

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BATH ORIGINAL

Hydraulic fluid and prevents the flow the effect of the blank weight practically completely, so that the blank used from the one under his Hydraulic fluid located at the foot end is carried In order to facilitate the initial phase of extrusion, the head end of the blank can be made in a suitable manner be preformed.

When the ram 58jsr is pushed in, it initially arises due to the increased pressure a stronger flow around it of the blank through the hydraulic fluid via the

Expensive surface 65 of flow control element 62. J

As soon as the head end of the blank approaches the control surface 62, the gap cross-section between them increases both parts, and the flow is throttled. This valve action causes a pressure increase in the Hydraulic fluid emerges in the area of the blank head. From the chamber 64 via the deformation zone 69 in the passage 6? between blank and control surface liquid flowing therethrough also suffers a pressure drop.

The flow between the control element 63 and the blank 65 exerts a pressure with axial and radial components on the head of the latter. The former move away% lower, whereby the piston acts as a blank acted upon the pressure fluid in the chamber 64 into the chamber 64 in the blank in the direction of the control 62nd The level of the pressure acting against the foot end 70 of the blank is less than the effective axial component of the pressure acting on the head of the blank or that in the entrance area of the deformation zone 69 due to the advance of the

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Control element 62 generated pressure. From the above Explanations result that »the pressure: on the foot end of the blank with that on the head end increases, but at a slower rate while A pressure drop occurs in the fluid flowing between the blank and the control surface, which is caused by, among other things the constriction or throttling of the flow as a result of the valve action between the blank and the control surface is caused. These relationships are in Fig. 4 shown in the form of a force and pressure diagram, which the on the blank during the extrusion process in the device according to FIG

• shows the acting force and pressure components. '■.' . '"■■''■■■■' ■ '' ■: '■' ■ '

Three essential points are marked on the blank 65 in FIG. 4, namely the entrance Λ of the deformation zone, the exit B of the deformation zone and the position C the face of the blank foot end. The place A corresponds to the point of highest pressure in the system, since the hydraulic fluid from this point in both Directions, namely from the point .v to the point B over the deformation zone 69 and from point A to Place C between the peripheral surface of the blank and the surface of the bore 52 therethrough. As a result of the narrow gap 76 between the blank and the bore 52 ■}, however, there is a high flow resistance here, see above

that the flow is mainly about the control 62 runs.

oil flow over the deformation zone between the Points A and B calls because of the flow restriction between the control surface 63 and blank head a decreasing Pressure on the head surface of the blank. The pressure acting here has both axial and also radial components. The on that

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BATH ORIGINAL

Axial components acting on the conically tapering head end of the blank correspond to an effective pressure P _ea on the projection area A _{1 of} the conical blank head, which _{corresponds to the cross-sectional area A 2 of} the blank base minus the cross-sectional area A- of the emerging product or wire 7 Areas are indicated by dash-dotted lines in FIG. 4.

_{The axial pressure P Ä} _ acting on the blank is generated

θα

an axial force F ₁ which drives the blank away from the control surface 63. The following applies here

Apart from the fluid friction within the flow between the blank on the one hand and the control surface 63 and the bore 52 on the other hand, the force F ₁ is transmitted undiminished via the blank to the fluid behind the foot end 70. _{The force F 2} acting on the latter is equal to the product of the cross-sectional area A ₂ and the pressure P:

F ₂ - P _c . A ₂ (2)

Because of the equilibrium of forces on the blank, F _{1 is} equal to F ₂ , so that equations (1) and (2) result

^P ea ^A 1 ^{β P} c * ^A 2 *

Since the area A _{2 is} larger than the area A ₁ , equation (3) can be used as
is less than P _EQ .

_{2 1}

Equation (3) can only be fulfilled if P

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Since P is the axial component of the effective pressure of the passing through between control surface 63 and blank

Is liquid, the pressure P _n must be at the inlet of the

Deformation zone necessarily greater than the pressure P so that the following applies:

^p a> ^p ea> ^p o «♦>

When the ram 53 and the control element 62 advance in the initial phase of the work process, the outflow from the chamber 64 is progressively constricted. This causes a pressure increase in the Wk liquid at the head end of the blank, which in turn causes corresponding forces transmitted from the blank to the liquid at the foot. Because of the proportionality of these forces to the cross-sectional area A ₂ or the projection area A ₁ , there is a more rapid pressure increase at the blank head compared to the end face of the blank base.

The consequence of this are different stresses in the material. An element of the blank material at point A is shown in FIG. 4 under the action of the associated radial and axial stresses S _r and

S "and S shown. S “moves from that to that ^ ea c r

W pressure acting on the circumference of the blank at point A,

while S _{Äe depends} on the sum of the axial components of the ea

Pressure on the blank head and S _Q comes _{from the pressure P 0} acting on the blank base. Since the magnitudes of these stresses are directly related to the associated pressures, the radial stresses also increase faster than the axial stresses

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temporal voltage rise is shown in Fig. 5, in the form of a diagram of the radial and axial stresses over the advancing advance position of flow control element 62.

5 illustrates the inequality of the temporal increase in the radial _{stress S r} and the axial stress S ₃ both during the initial phase and during the further course of work. The increase in stress lasts until the stress-generating pressures have reached a value at which the difference between the radial and axial stresses S_ or S_ reaches the yield stress S of the material. At this moment the deformation and the extrusion process begin.

For a continuous deformation within the entire deformation zone, the aforementioned stress relationship must are maintained along the entire length of the deformation zone. According to the invention this is through a controlled flow of pressurized fluid between the control surface 63 and the head end of the blank 65 at equal pressures and flow velocities achieved.

The deformation of the blank material in the device shown in FIG. 5 is generally divided into three Describe stress states:

a) The material is under tension, but is not in the state of deformation, namely in the Chamber 64 before entering the deformation zone j

b) the material is under stress accordingly the state of deformation, namely

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Over the entire deformation zone 69 ;

c) the material is relaxed or is still under certain stresses, but not in the deformed state, namely in the area after leaving the deformation zone.

The aforementioned tension relationship, according to which at each Place of the deforming material a difference at least corresponding to the yield stress must exist between the principal stresses, means for the conditions according to Fig. J5 that the radial stress on each material element within the deformation zone the axial stress must exceed the yield stress by an amount at least equal to. Maintaining this state with the aid of a controlled flow of pressure fluid according to the invention can be understood in detail from FIG. J5. Reference is made to three points X, Y and Z for explanation taken, which three places within the deformation zone in the area of the entrance (point A), between the points of the deformation start andfat the end of the deformation as well as in the area of the exit the deformation zone (point B).

At point X there is a radial stress component P corresponding to the radial component of the pressure of the liquid flowing at point X, an axial component which results from the pressure P _n acting on the base of the blank, and a stress P 1 which results from the sum

Sat

the axial components of the pressure acting on the blank head in the deformation zone. A Material element at point X is therefore subject to a Tension S corresponding to pressure P,

ΛΓ Λ

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a voltage S corresponding to the pressure P and a

Tension S corresponding to pressure P. To the up ~ sä sa

The right maintenance of the deformation beginning at the point Λ at point X is therefore a difference between the radial stress S "and the axial stress S _e _ as well

ΧΓ So

S at least equal to the yield stress of the material

necessary.

At point Y (Pig. 3) is the pressure P, which is from the

tr

The fluid flow onto the material surface, which has an increased velocity and its radial cross-sectional expansion, is reduced, as a result of the increase in velocity and, consequently, the energy expended for the deformation and for overcoming the fluid friction in the flow has fallen to a lower value. At point Y there is thus a tension P _r (radial component of the pressure of the flowing liquid in the deformation zone at point Y), P "" (sum of the axial

sa

components of the pressure on the section of the ingot head downstream of point Y in the deformation _{zone) and P sa} 2 ( ^{pressure p} _c minus the sum of the axial pressure components on the portion of the ingot head upstream of point Y in the deformation zone).

The material element at point Y is therefore subject to a j

Tension S corresponding to the pressure Py ₁ , * a tension ^S sa ^ent P ^{recnend the} pressure P _sa ^ and a tension corresponding to the pressure P ~ _o. To maintain the deformation, the difference between the radial stress S- and the axial stress S-

and S - evenly over the yield stress of the saw

Material are held.

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At point Z, the pressure of the flowing liquid has reached its minimum because of the aforementioned effects, while the flow velocity has increased further and the radial cross-sectional thickness of the flow has further decreased. The following pressures act on the material: P _n ,,, (radial component of the pressure in the flowing liquid at point Z in the deformation ζ one), P „ _Q (axial component of the

Za

Pressure of the flowing liquid in the deformation zone at point Z) and P ^ * * (pressure P _n minus the oume

Sa,.? C.

the axial components of the pressure acting on the blank head above point Z in the deformation zone). A material element at point Z is therefore subject the following voltages: s "corresponding to the pressure P" ",

Zi zr

S ", corresponding to the pressure P" and S "" - * corresponding to

ZX. Z a 5α. JJ

the pressure P _sa 3 "At this point, too, shortly before the material emerges from the deformation zone, the aforementioned tension is maintained, ie the difference between the radial stress S" and the axial stress S _ and S ₀₀ - is again above

ZcL SS.?

the yield stress of the material.

It follows from the above that the effect of the flow control element 62 with its control surface is essential for compliance with the given conditions and the deformation process. The control surface can, as shown in the example, be conical with straight surface lines, but possibly also with non-straight surface lines are executed. The determination of the cross-sectional shape or the shell shape the control surface can be done empirically. It was also found that the angular position

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the surface of the blank in the deformation zone

3. * ~ * Oil GT * ^ T * ^ P '"\

on the one hand and the corner of the control surface 63 / on the one hand deviate in such a way that calibrate in the direction of the exit of the deformation ζ one a mnähun-j the control surface on the one hand and the blank oüerflache on the other hand results. For every application in an extrusion or extrusion process can be an optimal form of the oteuerflache for determine the execution of an extrusion process with maximum efficiency.

As mentioned, the maximum pressure P occurs in the pressure medium system in the inlet area of the deformation zone, ie m of the otelle λ . Equation (4) resulted in a P greater than P despite the connection between the corresponding pressure initiation areas via the gap 76. This phenomenon occurs in the device according to the invention according to F ¹ Ij. 3 in spite of the uniform pressure transmission on all sides in a liquid , since the small width of the gap J6 forms a strong constriction for the pressure medium flowing around the blank from the head to the foot end. ) This οtröiiiungseinschnürun j enables the maintenance of a difference between the pressures P _Q and P, whereby, in the example, a substantially

linear orueki fall between positions A and C. over the otrömungswe; in gap 76 results.

The dimensioning of the gap JQ can be made from the required pressure difference between P and P, from the viscosity of the

109818 / 129S bad

Pressure medium at the ambient pressure and from the permissible Flow velocity can be determined along the surface of the blank, where it is for the The latter size is an estimated value close to zero flow velocity can.

The pressure-reducing effect of the flow constriction a constriction also acts in the narrow gap 76 (FIG. 3) of the blank during the extrusion process, i.e. premature deformation before entering against the deformation zone. In detail, act on a material element at point Λ (Fig. 4) the following tensions!

The one generated by the pressure P "on the material surface Radlais tension S, which is caused by the pressure P on the foot

A C

Front surface of the blank in the chamber 64 acting pressure P _c generated tension S _Q and the sum of the Axla! Components of the pressure P _ea on the foot

cä

The end face of the blank generated stress S _ee . the

© SI

Deformation begins at point A, so that the magnitude of the radial _{stress S e is} greater than that of the axial stresses S_ and S_ _Q , namely by

c sa

an amount corresponding to the yield stress of the material. Since the blank surface is nowhere between the points A and C has an inclination to the blank axis, so here, d, h. upstream from the control element 62 applied pressure no change the axial stress in the material. The radial pressure, meanwhile, increases between points A. and C linearly, which results in a corresponding reduction of the radial stresses in the material Upstream from point A isfc accordingly

1O961Ö / .12 $ S BADORiGlNAL

the difference between the axial and radial stresses Always lower in the material than the yield stress, which results in undesirable deformation, in particular a constriction, redeem in this area.

With reference to the pressures at or stresses in the product 74 leaving the deformation zone, it was already noted that the ambient pressure at the exit of the deformation zone can correspond to atmospheric pressure or some other suitable pressure value.Any counter pressure at this point should not, however Be high so that the yield stress Excessive differential stresses can set in the material μ , otherwise further deformation would occur.

Now the running in the steady state of flow becomes Main phase of the work process explained. The criteria of this state of equilibrium are has already been stated above. It can be seen from FIG. 5 that this equilibrium state results when the voltages S and S stay constant.

In the final state of the initial phase of the work process had the said state of equilibrium with ^

incipient deformation and the necessary Pressures and tensions adjusted. If now the deformation »resistance and the yield stress, for example the value S according to FIG. 5 * is essential remain constant, every amount of the punch and control element feed is displaced from the chamber 64 voluminous of blank material and hydraulic fluid,

106818/1296

the Ira stand constant relationship to each other and together with the insertion volume of the control element correspond. The advance of the control element into the chamber 64 thus has a displacement of volumlnar des Material and the hydraulic fluid result that because of the equilibrium flow state in the system during the entire extrusion process to each other in constant Relationship.

As the size of the for initiation and maintenance The pressures required for the flow process can be determined from the flow stress of the material and in the assessment of the balance between the

W control surface 63 and the head of the blank expresses,

This results in a pressure profile that is constant over time for a material with uniform yield stress over the blank and temporal constancy of the distance between the blank surface and the control surface along the deformation zone, the thickness of the Liquid layer between the control surface and the Blank head changes along the control surface.

In practice, however, changes in the deformation generally occur with commercially available material. resistance and hardness, which result in corresponding changes in the flow process.

Such inequality of memory properties can, however, according to the invention automatically be compensated, especially for changes in hardness of the blank raw material applies.

Fig. 6 shows a flow "expensive" ifflinfc 62 developed ;? speaking to the one just & fts # 1 $, 3 * where

-31

BATH ORIGINAL

different positions of the blank head in relation on the control surface 63 are indicated by dash-dotted lines * There is a gap in the fully extended position E between blank surface and control surface. This distance corresponds to the position of the blank in the initially set equilibrium flow state with the criteria already mentioned, whereby the pressure in the chamber 54 on the basis of a flow stress or a deformation resistance S "^ of the blank material remains constant (see Fig. 5). In this state, the position of the blank remains with respect to the control surface constant.

Now, when a hard spot with a higher yield stress occurs ^ira material, we get the following "

a) the advance of the control element 62 remains at a constant speed in the direction of arrow 60 exist;

b) decreases because of the increased resistance to deformation the blank at the smaller distance F to the Stetler surface 63, with which a correspondingly world-wide Constriction of the pressure medium flow over the Control connected 1st}

c) by the constriction of the current going on around the world between the control surface and the blank, the pressure in the flowing liquid increases in this area continues on, associated with an increase in the axial force removing the blank from the control surface;

d) the increase in the aforementioned, In the deformation « The axial force generated in the zone moves the blank

109816 / 129S

further into the chamber 64, which is associated with a rise in pressure on the foot end face of the blank., .., ■; is; -i

e) the aforementioned pressure increase continues until there is a need to overcome the increased flow stress Sg of the harder material has set a sufficient difference between radial and axial stresses and the flow process can proceed.

There is now a state of equilibrium at a higher pressure level, ie with correspondingly increased values for P _ft , P and P _c , corresponding to the. increased deformation and flow resistance of the material. This results in the same flow speed as before the entry of the harder material point into the deformation zone. The processes explained step-by-step above actually run practically at the same time, so that there is an extremely rapid adaptation and automatic regulation with the product exit speed being kept constant.

If the material is subsequently softer again, i.e. material with a lower yield stress than S and a correspondingly lower need for radial and axial stresses for a nearly constant flow rate enters the deformation zone, it begins without changed setting of the pressure, a more rapid deformation, leading to a greater distance between Rohllngskopf and control surface leads, for example in accordance with the distance α indicated in FIG. 6. The associated reduction in the druok drop in the flow between the blank head and

109818/1298

BATH ORIGINAL

The control surface also has a reduction in the axial force pushing the blank into the chamber 64 result »so that the blank again in the direction of the position semäss distance Edirch the effect of the pressure acting on the blank foot is advanced in chamber 64 · This displacement continues until the pressure in the chamber 64 and the pressures acting on the blank head within the deformation zone again corresponding to the equilibrium flow state Values are reduced. It is also the result of the subsequent passage of the softer material again a constant flow and exit velocity in a state of equilibrium.

The device according to the invention thus enables in all an automatic regulation of the pressures and tensions in terms of setting and maintaining a Balanced weight flow state with constant product exit velocity independent of changes in the properties of the material, the latter being constant from contact with the surface of the die is kept away. The result is one that is in any case not adversely affected by the extrusion process. Degree of uniformity in the distribution of the physical properties of the material in the Product and a reduced need for drive power for the extrusion process

The final phase of the work process again includes a complete deformation of the material supply in the blank, as has already been explained above, or else a previous termination by withdrawing the flow control element 62.

-34 -

109818 / 129S

BATH

In the following some exemplary numerical values for the device according to the invention according to FIG. or the associated procedure specified:

An ingot-shaped blank was obtained by extrusion molding with the following process and facility data processed (extruded) i

blank

Length 109 cm Ausaendurohmessert 0.91 cm Cone angle of the head
absohnittest 30 ° Material Aluminum Pressure vessel Length from the entrance of the
Deformation zone up to
at the end of it
Start of operation 1 to 8.1 cm Bore diameter 0.954 cm.

Flow control learn nt Durohmesser the Outlet opening t 0.114 cm Cone angle of Flow control surface 40,

straight surface lines of the conical surface Feed speed approx. 13 m / min.

Hydraulic fluid commercial product "Cindol 4683"

(registered trademark ) ₉ a lubricant for smelting aluminum.

- 35 -109818/1295

BATH ORIGINAL

River jgkeltsdrucke

Pressure P at the foot end _P

of the blank ι 7.730 kp / enT

Pressure P at the entrance of the _2nd

Deformation zone: 8, ^ 35 kp / cm

Pressure P _b at the outlet of the

Deformation zone around atmospheric pressure,

Extruded product outer diameter: 0.119 cm

Lungs: 73 »2 m

Exit speed 1220 m / min.

When executing the device according to the invention According to FIG. 7, the pressure fluid is in the entrance area of the deformation zone of which the foot end of the blank acting pressure fluid separated by a seal, so that different fluid lengths in the two Pressures can prevail. The extrusion device designated here as a whole by 80 comprises a pressure vessel 81 with a bore 82, in which - for example with a shrink fit - a JSylindjfrsches Housing 83 is firmly inserted. This case has a coaxial bore 84 with a thread 85 on one end and an inwardly projecting shoulder 86 on the other end and one as well coaxial counterbore 87, which the latter extends from the shoulder 86 over the rest Body of the housing 83 extends.

Sin plug 89 1st with a screw connection in the Housing 83 inserted and supports the closed end 91 of a cylindrical sleeve 90, which in turn

- 36 -

1Ö9Ö18 / 129S

-56- 20A7931

is firmly leashed into the bore 84. The sleeve 90 extends coaxially within the bore 84 from the plug 89 to its open end 92, which with Distance from the shoulder 86 is arranged. A sealing ring 94 »for the one version accordingly the seal 71 according to Pig. 3 comes into embossing is inserted in the bore 84 between the plug 89 and the sleeve 90 to prevent the escape of liquid to prevent the plug 89.

A sleeve 95 is slidable in the bore 84 between the open end 92 of the sleeve 90 and the Shoulder 86 inserted in the sleeve 95 is a coaxial bore 96 for the introduction of an ingot or Rod-shaped blank 100 is provided. Furthermore, a sealing ring 97 is arranged on the end of the sleeve 95 adjacent to the shoulder 86, around the passage of liquid between the sleeve 95 on the one hand and the bore 84 and / or the blank 100 on the other hand to prevent at the bore 96 when the liquid in a chamber 98 surrounding the blank is above the shoulder 86 is put under pressure in a manner to be explained in more detail. When in the hole 96 over the sleeve 95 inserted blank is thus the internal volume of the pressure vessel 81 in the first, already mentioned chamber 98 between the counter bore 87, the sleeve 95 and a flow control element 101 on the one hand and a second chamber 99 divided, the latter through the bore 84, the sleeve 95 and the closed end 9I of the sleeve 90 is formed.

BATH ORIGINAL

A passage 102 formed in the housing 83 has a first opening that is flush with the chamber 98 103 and a second opening 104 communicating with the second chamber 99. The opening is arranged between the open end 92 of the sleeve 90 and the shoulder 86 in such a way that at If the displaceable sleeve 95 rests in the end 92 of the sleeve 90, the opening 104 is covered and somfc a liquid can pass between chambers 99 and 98.

In the first chamber 98, a cylindrical punch 106 is mounted in a telescopic manner in the eye bore 87. The advance and retraction of the punch 106 are effected by a press or the like, not shown, as indicated schematically by the arrows 107.

The flow control element 101 is connected by screwing to the chamber-side end of the plunger 106 and has a frustoconical passage with a control surface 110 for the _{pressure fluid emerging from the chamber 98 (} via the passage 109 into a coaxial channel in the plunger 106) Outlet for the wire-shaped product 115 to be produced from the blank 100.

A seal 112 is in an annular recess between the control element 101 and the punch 106 arranged and prevents the escape of liquid from the chamber 98 along the punch 106 at

-38 -

109 * 18/1295

§AD ORIGINAL

Extrusion plant. The design of the seal 112 can also be of the seal already described 71 correspond,

The following applies to the operation of the facility according to Pig, 7;

The chambers 98 and 99 are with a suitable pressure medium, for example with a pressure fluid filled like silicone oil or castor oil. A blank 100 is inserted through the bore 96 in the sleeve 95 so far inserted that its Pußenede 116 with part of its circumferential surface within the chamber 99 lies, the blank forms with the sealing ring 97 and the bore 96 a barrier against undesired Connection between chambers 99 and 98. At On insertion of the blank, liquid is displaced from the chamber 99 and through it in this state free opening 104 in the passage 102 and further Driven through the opening 103 into the chamber 98, which the latter is not yet under pressure.

The punch 106 is then inserted into the bore 87 and thus advanced into the chamber 98, the latter also being pressurized, to be precise under a valve action corresponding to the embodiment according to FIG. 3, which is now under pressure Liquid pushes the sleeve 95 downwards towards the Contact with the end 92 of the sleeve 90, the opening 104 being closed and the two bodies are separated from each other «The further advance of the ram 106 leads to an increase in pressure In the Chamber 98 and corresponding axial pressurization of the blank head, causing the blank to continue

- 39 -100618/1296

BATH ORIGINAL

ΗΗ * -3ϊ ^'·: ■■ "■ · ■■■■■■,

is driven into the chamber 99 · The uyfruck in the latter chamber rises as a result, but is due to the difference in the cross-sectional area of the Blank foot on the one hand and the projection area of the blank head on the other hand less than the Axial force component generating pressure.

With further punch advance and pressure increase in the Chambers 98 and 99 are created for extrusion of the blank material required radial and axial stresses. As already explained in relation to FIG. 3 are the pressures generated by the advance of the punch 106 at the head end of the flow control element 101 biggest. The driicfce in the Chamber 98 therefore surpass those in Chamber 99

The pressure in chamber 98 creates radial stresses in the blank material, while the pressure in the chamber 99 acts on the foot end of the blank and axial stresses generated in the material. In the case of radial stresses that are higher than the axial stresses, the result is with a corresponding pressure increase in the system due to the punch feed, a deformation state of the blank, if the Radla1-Axia! voltage difference is accordingly the pressure difference between the chambers 98 and 99 exceeds the flow stress of the material. Afterward the smooth flow state on the blank is set in the same way as in the execution according to FIG. 3 with the shaping and exit of the product 115 at a constant speed under the action of the pressure medium flow in passage I09 is maintained.

109818 / 129S

- 4ο -

The extrusion process with advancement of the punch 106 Chamber 98 can continue until the control 101 rests against the shoulder 86 of the counter bore 87 and the deformation of the blank is finished. The stamp is then withdrawn from the chamber 98, whereby the pressure in the latter drops below that in the chamber and the sleeve 95 in the axial direction up to Release of the opening 104 is shifted. The pressure in the chamber 99 is thus reduced without driving the blank head into the control surface 110 of the control element drained. After the stamp has been fully retracted the foot end of the blank is removed and the device is again in its original state for a new work cycle.

The main difference in the facility according to Flg. compared to that according to FIG. 3 there is darih that in the latter version, the pressure difference between the head end and foot end of the blank by a substantially linear pressure measurement within the narrow gap through which the pressure medium flows is generated on the circumference of the blank, while these two fluid areas in the embodiment according to FIG. 7 physically separated from one another during the extrusion process are and thus no flow can occur along the surface of the blank in the counter bore 87. As a result is the entire blank surface within the chamber 98 under the same pressure, namely that at the entry area of the deformation zone. This pressure is so high that the axial stress in the Raw material by at least the flow stress

- 41 -

109Öi8 / ia9S bad ORIGINAL

excessive radial stress is generated and thus in the entire blank area within the chamber 98 a deformation, namely a constriction of the blank can occur. This means a malfunction, since the hydraulic fluid is then in the forming Hollow rib on the circumference of the blank as over the deformation zone flows out of the chamber 98, as would correspond to the desired flow process. The blank head would then also come into direct contact with the control surface 110, so that in place of the flow extrusion process a mechanical extrusion process would occur.

The constriction of the blank is in the embodiment according to FIG. 7 by correspondingly narrow dimensioning of the Gap between blank and counterbore 87 is met in such a way that there is a comparatively high flow resistance in this gap (similar to also with the version according to Fig. J5). At the beginning of a constriction of a blank section would therefore have to get liquid through the gap flowing in forming cavity, but this is due to the high flow resistance is hardly possible. In the area of the incipient constriction occurs accordingly an immediate pressure drop, which counteracts the tendency to constriction and cancels it. Furthermore, the discharge of the pressure medium flow in the vicinity after an incipient constriction due to the high flow resistance exert no adverse influence on the outflow via the deformation zone 109 to the blank head, so that the flow process proceeds undisturbed.

- 42 -

The slow penetration of hydraulic fluid from the vicinity of an incipient constriction can, however, under certain circumstances lead to a replenishment of the lower-acting pressure and to a slow porting of the constriction. In most of the materials that can be used for the present deformation, however, a solidification occurs with the deformation, ie an increase in the yield stress. As a result, the progressive constriction encounters a comparatively higher resistance. In this way there is a self-correction of the tendency to constriction up to a certain degree. In the W Practice has shown that in any case controlled in conjunction with an appropriate gap dimensioning in accordance with the preceding explanation, the Einschniirneigung of the blank and an undisturbed flow of the working operation can be ensured.

During the deformation of materials with the help of a controlled flow of pressure medium, it was found that that a position of the maximum pressure at a point in the area between the start of the deformation and the end of the deformation, i.e. within the deformation zone, is necessary can be. This phenomenon is due to a change in the properties of the material deformation or work hardening.

With such a P form-fitting flow deformation radial and axial stresses are generated in the manner already explained with a difference that is at least equal to the yield stress of the material. With some materials, the

- 43 -

103818 / 129S

SAD ORIGINAL

Initial phase of deformation such a solidification with a rapid increase in the yield stress results in further deformation without an increase in pressure in the deforming pressure medium, e.g. in the extrusion fluid, is no longer possible.

For further explanation, reference is made to FIG. 8, which shows the course of the pressure in an extrusion liquid during extrusion on a blank as well as the course of the flow stress of the blank material with a deformation from a radius of 0.46 cm to a radius of 0.057 cm shows. The curve of the yield stress refers to *

an aluminum alloy (EC-aluminum) and resulted -

from measurements made of the yield stress at the deformed head end of a blank. There is a rapid increase in the yield stress at the beginning of the deformation with a gradual flattening of the curve in the subsequent area. This increase in the flow stress makes a corresponding increase in the pressure of the extrusion fluid necessary to maintain the flow process. This is reflected in the curve desJExtrudierflüssigkeitsdruckes that obtained by calculation of pressure values on the basis of, extrusion process of a blank of the aforesaid aluminum alloy A

became. This example is the reshaping of a rod-shaped blank with a diameter of 0.91 cm into a wire-shaped product 0.114 cm in diameter using castor oil with an addition of 10 ^ Percentage by weight of molybdenum disulfide as extrusion fluid underlying. For the curve of the extrusion liquid pressure the following equation applies:

109818/1296

2047331

~ Y2 ) J

Herein means:

S ^ the pinning stress of the material on the upstream located end of a material volume in the process of deformation, which extends over the cross-section of the blank extends!

Y ^ is the radius at the upstream end of the volume of material being deformed;

Y _{2 is} the radius at the downstream end of the volume of material in deformation j

P _{1 is} the pressure of the fixtruding liquid at the upstream end of the material volume in deformation

«The pressure of the extrusion fluid at the downstream located end of the material volume in deformation

Sp is the axial stress in the deforming material at the downstream end of the volume element and

- 45 -

BAD ORiQINAL

10981 8 / 129S

θ is the angle between the surface of the deformation the material volume and the longitudinal axis a flow control element within which the deformation of the material takes place.

The curve of the extrusion liquid pressure is straight Pig. 8 is based on the assumption that the angle 9 is constant at all points during the deformation, with the exception of the first entry surface of the material into the deformation zone. In this entry surface the angle θ became zero degrees at the original Entry point to a value of 20 ° at an estimated point within the deformation zone changed, which is followed by an area with a constant angle of 20 ° for the purposes of the calculation.

As can be seen from the curve, the extrusion fluid pressure has a maximum between the beginning and the end of the deformation zone, the position of this pressure maximum is in the longitudinal direction of the deformation zone pretty clearly determinable. As mentioned, in the example there was a between the exit end of the Deformation zone and an assumed point downstream of the entry end of constant surface angle of the blank section undergoing deformation, where / this surface angle between the accepted point and the end of entry of the deformation zone 0 goes back. This assumed point may or may also coincide with the position of the pressure maximum be arranged further upstream «Because of the conical shape of the material surface between the Point of highest pressure and the outlet end of the

- 46 -

BATH ORIGINAL 1Ö9818 / 129S

Deformation zone represents a longitudinal section of the material undergoing deformation, a right-angled triangle, the hypotenuse of which is formed by the surface of the material between the end of the deformation and the point of highest pressure, while a cathetus of the triangle through a radius of the blank at the point of highest pressure and the opposite angle of the triangle is formed by the surface or cone angle (half the value of the apex angle) Q. In the example, the deformed head of the blank has a radius of 0.371 cm at the point of highest pressure. The position of the point of highest pressure in the longitudinal direction is thus the puncture of the blank radius at this point. The longitudinal distance between the exit end of the deformation zone and the point of highest pressure within this zone is equal to the change in the blank radius between the point of highest pressure and the exit end of the deformation zone multiplied by the cotangent of angle 9.

As already mentioned, the place is highest Pressure during a form-fitting extrusion process at the leading edge / les advancing flow control element (i.e. at the front edge of the element, seen against the feed direction). To now the The point of high pressure generation and the high pressure point for maintaining the flow process coincide some of the deformation occurs upstream of the boundary of the flow control element and is therefore not subject to the conclusions Scheme in the sine that the deformation

109818 / 129S

- 47 -

BATH ORIGINAL

by the pressure medium flow in the area of the control surface is kept automatically within the specified parameters and operating parameters.

In this context, a certain embodiment of the device according to the invention enables the deformation range of the material completely to hold within the flow control element and the deformation thus form-locking, i.e. inevitable within the specified values due to the pressure medium flow occurring during the deformation process to regulate constantly in the intended catfish. According to the invention, this is done by injecting pressure fluid in the deformation ζ one reached, namely at a point within the flow control element, whose position corresponds to that of the highest pressure. For this purpose, after determining the location of the Pressure maximum from a diagram in the manner of FIG. 8, a DruckraittelzufUhrung at the corresponding point of the flow control element is provided, from where the pressure medium both upstream and downstream flows off and along the surface of the deforming material a pressure curve according to Fig. 8 is generated.

An embodiment of such an extrusion device according to the invention emerges from FIGS. 9 and 10 or 12. The total here with the Device provided with reference numeral 210 urafasfc a pressure vessel 211 with a bore 212, which the latter is closed at one end by a sealed plug 213 (see FIG. 12). That closed end of the Druok vessel

1Ö9818 / 129S _BAD

rigidly attached to a base 14. Inside the bore 212 there is an annular shoulder 215 a groove for receiving a sealing ring is provided. 'This shoulder divides the bore 212 into a forward, i.e., upstream, section 216 and a rear, i.e., downstream, section located section 217.

Inside the rear bore section 217 a cylindrical punch 218 is inserted telescopically through the open end of the pressure vessel 211, its feed movement according to the arrows

220 is again carried out with the aid of a press, not shown, or the like. In the pressure vessel-side End of the punch 218 is a threaded eye hole 221 for attachment a flow control element 222 is provided. Furthermore, the punch 218 has a coaxial LMngsbohrung 224 for the exit of an extruded Product 226.

The flow control element 222 comprises an elongated, substantially cylindrical body with a axial through-hole 228, the latter corresponds to in the diameter of the bore 224 of the punch and forms together with the latter bore an exit channel for the product 226. The rear, i.e. downstream, and in Fig. 9 end of the flow control element located on the left 222 is with one in the counterbore

221 of the punch screwed in thread extension 229 provided «

109818 / 129S bad original

The diameter of the peripheral surface 231 of the main portion of the flow control element 222 is in substantially equal to the diameter of the inner surface of the sealed shoulder 215 so that a There is a conductive sealing connection at this point. The front, i.e. upstream end portion 2j5j5 of the flow control element 222 faces against it has a larger diameter, which corresponds to that of the front section 216 of the bore 212 and thus a limit stop for the sliding movement between the control element and the pressure vessel forms. The circumferential surface of the end section 2J53 of the Control element 222 has a plurality of longitudinally extending, groove-shaped channels 2j54 provided, over which the hydraulic fluid is free can flow through.

In the front end section of the control element 222 is a frustoconical depression provided, the a control surface 240 for influencing the deforming Forms pressure medium flow. The volume of material encompassed by the control surface forms a deformation zone 242, within which the entire deformation of a 3-tab-shaped blank 244 into a product 222 takes place goes.

There are a plurality of openings in the control surface 240 245 as the mouths of associated longitudinal channels 246 of the Control element 22j is provided. Each longitudinal channel 246 is via a radial channel 248 within the Control element with the between the outer surface of the latter and the bore 217 located pressure fluid quantity in connection. The openings 245 are within the deformation zone at

- 5o -

109818/1295

Place of the highest liquid adruoke, which is necessary for the extrusion of the material 1st.

The diagram according to Fig. 8 shows, for example, that for a made of an EC aluminum alloy with an outer diameter of 0.91 cm for implementation an extrusion ratio of 64: 1 the maximum pressure at a diameter of 0.751 cm occurs. This results in the position of the openings 245 within the deformation zone 242 from the size (0.371-0.057) .cotan O.

The peripheral surface 231 of the control element 222 forms with the inner surface of the rear part of the bore 217 and with the punch 213 and the Shoulder 215, an annular pumping chamber 250 which is filled with the extruding pressure fluid. The latter is fed into the pump caramer 250 through a channel 252 in the pressure vessel 211 from a feed line 253 supplied with a check valve 255.

Similarly forms the peripheral surface 231 of the control element 222 with the front face of the shoulder 215 ″ of the inner surface of the front bore abaohnitts 216 and the front Sndabsohnitt 233 of the control element a chamber 260, in which the pressure fluid During the deformation of the blank can occur via the channels 234 · The advance of the punch with the control element 222 causes a volume reduction of the filled with hydraulic fluid Pump chamber 250 and an increase in volume of the chamber 260 receiving the pressure fluid.

- 51 -

109818 / 129S

BATH ORIGINAL

As a result of these opposite volume changes results the desired pressure flow rate across the deformation zone with form-fitting flow pessits according to the invention

For the operation of the device 210 sioh results with reference to Pig "9, 10 and 12 the following"

The control element 222 is in the operating state sealed the end of the pressure vessel 211 in the bore 212 until reaching through the shoulder 215 inserted and then screwed to the punch 218. Then the blank 244 is in the front portion 216 of the bore 212 is inserted. The head section of the blank can optionally be preformed in a suitable manner for this purpose. After this Filling the system with hydraulic fluid, the plug 213 is screwed into the pressure vessel and the latter attached to the base 214.

The front portion 216 of the bore 212 and the front end portion of the control member 222 form with the plug 21> one the blank and the pressure medium receiving chamber 262. The blank is within this chamber of the as a pressure medium provided wing area "with a distance from the bore 212 on all sides.

After inserting the blank and the punch with the control element 222, the latter is in the bore 212 inserted, resulting in a corresponding relative speed compared to the blank

- 52 -

10Ö818 / 129Ö

This creates a pressure increase in the pumping chamber with the oil flow of the coal blow valve 233 Volume reduction of the pumping chamber 250 is simultaneous Hydraulic fluid Via channels 248 and 246 and via the openings 243 for injection into the Deformation zone 242 brought. The pressure fluid exiting here divides into an upstream fluid and into a downstream flow. The former occurs through the gap between the blank head and the rear part of the control surface 240 into the chamber 262 surrounding the blank and via the Channels 234 continue into chamber 260. The other flow intervenes downstream from openings 245 Blank head and control surface through and exits the device via channel 224 together with the Product 226.

Various volumetric relationships arise during the operation of the device. That's how it is Volume of the liquid passing from the pumping chamber 250 into the deformation zone 242 is equal to the sum that of the upstream and downstream partial flow through the deformation zone guided volumes. The increase in volume of the chamber 260 η is also equal to that of the upstream directed partial flow guided through the deformation zone and out of the chamber 262 rings of the blank 244 during the advancement of the control element 222 displace volume.

That with a certain feed distance of the control element 222 and the punch 218 out of the chamber

BADORiGINAU

.53 -

The displaced volume is determined by the transverse surface area of the pumping chamber 250 and its dimensioning can be derived from that fluid volume which is required to maintain the pressure center Is flow corresponding to a continuous deformation of the blank in the deformation zone 242.The pressure fluid entering the deformation zone has its own highest pressure in the area of the openings 245, to which there is a pressure drop upstream and downstream with a profile approximately according to Pig. H connects. The absolute values of the required amount of liquid and the introduction pressure result from the properties of the material to be deformed, from the extrusion ratio, the properties of the pressure medium and the feed rate of the control element 222. The volume and pressure values can be determined empirically for the respective application. Using the device according to the invention, the extrusion can in any case be carried out under ideal conditions and with a minimum of drive energy if the shape of the control surface 240 and the amounts of pressure fluid introduced from the pumping chamber 250 into the deformation zone are appropriately determined.

In summary, it can be stated that the last-described embodiment of the Invention of a molded 3-flow extrusion by injection of pressure medium into the deformation zone within a flow control element under maximum pressure and at the point of maximum pressure can be realized, with the deformation completely

1 0 9 8 1 8/1 2 9 p

takes place within the deformation zone provided for this purpose * by the control surface 240. At the same time, there is an automatic control of the operating greetings according to a constant equilibrium flow condition.

In the example embodiments of the invention described, it was assumed that the exit of the molded product takes place essentially against atmospheric pressure. The flow extrusion molding process according to the invention can, however, in principle even if the product escapes into an environment with a higher pressure than atmospheric pressure.

In any case, the use of the method or a device according to the invention offers itself naoh the invention the possibility of a material by the action of a controlled pressure medium flow to deform in continuous extrusion, whereby strand-shaped products of uniform diameter and distribution of strength and other physical properties over the product length '. As a result of the deactivation direct solid body contact between the material to be deformed and the mold or other surfaces of the device according to the invention the occurrence of periodic changes in the product exit speed with corresponding irregularities is not only avoided, but also allows implementation of the Verfarensalt minimal drive energy.

109818/1296 bad original

Claims (1)

Expectations Method for deforming materials with the help a fluid pressure medium, a material being pressurized, and an extrusion process is subjected to the shaping of a product, characterized in that the material within a controlled flow of pressure medium is performed and that the deformation by the Effect of the pressure medium on the material, which is also under pressure, is brought about will. 2. The method according to claim 1, characterized in that that the pressurized material within the pressure medium flow in a to flow direction of the same continuous movement is performed. 3. The method according to claim 1 or 2, characterized in that the material with a first Pressure to generate axial stresses and with a second pressure to generate radial stresses is applied. 4. The method according to claim 3, characterized in that that the material is on its transit deposit Is held within the pressure medium flow under radial stresses, which the 109818/1295 ORIGINAL Axial stresses around at least one of the floating stress Exceeding the amount corresponding to the material. 5. The method according to claim j5 or 4, characterized characterized in that the pressure to generate radial stresses by the action of the pressure center Istromes is applied to the material. 6. The method according to any one of claims 3 to 5, characterized in that the material in the form of a bar-like blank with a in particular ^ blunt foot end and a) in particular tapered head end are used and that the foot end of the blank to generate axial stresses with the pressure medium is applied. 7. The method according to claim 6, characterized in that that the blank in the area of its head end to generate radial stresses with the Pressure medium is applied. 8. The method according to claim 6, characterized in that between the the front end of the The pressure medium acting on the blank and the pressure medium acting on the rear end of the blank Pressure medium a connection is established via a pressure-reducing flow path. 9. The method according to any one of the preceding claims, characterized in that the controlled flow of pressure medium within a passage a flow control element by feed this flow control element is generated against an amount of pressure medium. 109818/1235 BATH ORIGINAL 10. The method according to claim 9, characterized in that the passage has a control surface, and that the flow of pressure is under leadership this medium is passed along the control surface via the passage. 11. The method according to claim 9, characterized in that the passage has a control surface for generation an essentially converging flow of the pressure medium passing through it 12. The method according to claim 6, characterized in * that the pressurization of the pressure medium provided for generating the axial tension takes place by moving the foot end of the blank against the pressure medium, such that the generated Axial stresses are dependent on the feed force acting on the blank 13. The method according to any one of the preceding claims, characterized in that the pressure in the pressure medium as a function of changes in the The flow resistance of the material is changed in such a way that a predetermined exit velocity of the product of the shaping is maintained. H. The method according to claim 13, characterized in that that the foot end of the blank under corresponding Change of the pressure in the pressure medium with the flow resistance of the material matched Vorsohubkr & fteη is applied. 1Ö9818 / 129S 15 · Method according to claim 1, characterized by the following procedural specifications: a) a blank with an in particular tapering head end and in particular one blunt foot end is used in a DruckraittelfUllung; b) for generating a controlled flow of pressure medium between the head end of the blank and a control surface of a passage in a flow control element becomes the same subjected to a feed movement in the pressure medium filling «whereby the head end of the Blank and the control surface a constriction the pressure medium flow to increase the pressure acting on the head end of the blank form; c) the blank is subjected to a feed movement in the pressure medium filling to increase the pressure acting on its foot end, until the deformation of the blank material occurs; d) the progressive advance of the flow control element creates a continuous flow of pressure medium between the foot end and the head end of the blank as well as a progressive deformation of the blank material within the flow tax «elements generated; ·) The mean pressure! Flow within the flow «. The control element is changed accordingly (for the desired uniforming of the raw material into the desired Product regulated by the flow control element until it emerges. -5 - 1Ö9Ö18 / 129S BATH ORIGINAL 16. The method according to claim 15 »characterized in that that the pressure medium to generate a flow constriction In the area between the head end and the foot end of the blank on this flow path is passed through a narrow gap. 17. The method according to claim 15 *, characterized in that that the flow constriction of the pressure medium between the head end and the foot end of the blank by separating the one acting on the head end Pressure medium is generated by the pressure medium acting on the foot end of the blank. 18. The method according to any one of claims 9 to 11, characterized in that to generate a pressure medium flow along the control surface in Passage of the flow control element pressure medium in the area between the ends of this passage is injected. 19. The method according to claim 18, characterized in, that the pressure medium injection at maximum pressure and at the point of the maximum, for the Extrusion of the material required pressure takes place. 20. The method according to claim 18 or I9, characterized characterized in that part of the pressure medium flow in the same direction and another part of the pressure medium flow in the opposite direction to the flow direction of the materials. 21. The method according to claims 15 and 20, characterized marked that the direction of passage of the material opposite part of the 109818/1295 Pressure medium flow with that pressure medium flow which the pressure medium filling surrounding the blank leaves, is combined and that this combined pressure medium flow around the flow control is passed around. 22. Device for the extrusion of materials with the help of a fluid pressure medium a passage in a flow control element a shaping means is formed, characterized in that the surface of the Passage forms a control surface for guiding a pressure medium flow and that drive means for generating a relative speed between the material and the shaping means in the Are arranged so that the pressure medium forming a controlled flow under pressure is introduced into the passage and the material opens the passage within the pressure center thus generated current flows through. 23. Device according to claim 22, characterized. draws that means for injecting pressure medium between the ends of the passage and is provided for generating a controlled flow of pressure medium. 24. Device according to claim 22 or 23, characterized in that the drive means for The flow control element generates a relative speed between the material and the shaping means have feed device moving against the material. 109818/1295 BATH ORIGINAL 25. Device according to claim 24, characterized in that the device for injecting Pressure means one passage formed in the flow control element and one in dependence has pump means operated by the advance of the flow control element, the latter drives the pressure medium through the passage 26. Device according to one of claims 22 to 25, with a pressure vessel having a bore, characterized in that the bore of the pressure vessel has an annular shoulder, the volume variable with the flow control element and the wall of the pressure vessel Pumping chamber forms, and that in the flow control element at least one channel for the passage of pressure medium from the pump chamber the passage of the flow control element forming a control surface is provided. 27. Device according to claim 26, characterized in that that the bore of the pressure vessel is closed at one end and that one Part of the injected pressure medium after it Exit from the passage of the flow control element a receiving secondary chamber is provided 28. Device according to claim 27, characterized in that that in the outer surface of the flow control element recesses for the inlet of pressure medium are provided in the auxiliary chamber. 10 9 818/1296 ... . ■. · ■. ■ .. · ■■. ■ -.- ■■■ ^■■: ■■ · - · ■ ■■■ - ■■■ r ~ 29 Device according to Claim 26, characterized by the following features: a) the pressure vessel, the flow control element and the annular shoulder of the pressure vessel bore form a pressure medium pumping chamber; b) the pressure vessel, the flow control element and the annular shoulder of the pressure vessel bore form a pressure medium receiving chamber; ο) the flow control element and the closed end of the pressure vessel form a material-on take chamber; d) in the flow control element there is a plurality of the pump chamber with the passage of the flow control element connecting channels provided, such that pressure medium from the flow control element and pressure medium from the pumping chamber as a function of the advance of the flow control element is pumped towards the closed end of the pressure vessel. 30. Device according to claim 29, characterized in that part of the pressure medium coming from the pumping chamber flows into the pressure medium receiving chamber. Device according to Claim 29, characterized in that recesses connecting the pressure medium receiving chamber with the material receiving chamber are provided in the outer surface of the flow control element. 10 9 818/1295 ^BAD original 32. Device for extrusion of materials with the help a fluidic pressure medium «in particular after a One or more of Claims 22 to 31, characterized by a flow control element with a passage «in the at least part of the passage surface is designed as a control surface for a pressure medium flow serving to deform the material passing through, 33. Device according to claim 32, characterized in that that between the ends of the acting as a control surface Surface section of the passage in the flow control element has at least one pressure medium supply provided 1st. M. 34. Device according to claim 33, characterized in that that the pressure medium supply is arranged within the control surface in such a way that the entry of the pressure medium takes place in the area of the maximum pressure occurring during extrusion of the material. 35. Device according to claim 33 or 34, characterized in that the arranged in the area of the control surface Pressure medium supply a plurality of channels formed in the flow control element with openings between has the ends of this control surface. 1Ü9818 / 129S