DE7209275U - Extrusion device - Google Patents

Description

DR. BERG DIPL.-ING. STAPF

PATENT LAWYERS
8 MUNICH 86. POST BOX 86 O2 45

Dr. Barg Dipl.-Ing. Stapf, 8 Munich 86, P.O. Box 860245

Your sign Your ref.

Our sign

Our ref. 22nd

8 MÖNCHEN 80 MAUERKIRCHERSTR. 45

April 21, 1972

Lawyer file 22 191

United Kingdom Atomic Energy Authority London / England

"Extrusion device"

The invention relates to an extrusion molding apparatus.

For extrusion, a material located in a container is subjected to a pressure, which it by a

(0811) 98 82 72 98 70 43 98 33 10

Telegrams: BERGSTAPFPATENT Munich Banks: Bayerische Vereinsbank Munich 453

Postal check: Munich 653 43

Mold opening that determines the cross-sectional shape of the product squeezes out. The pressure on the material can be exerted mechanically, for example in conventional extrusion by means of a piston acting on the material in the container. During hydrostatic extrusion, the pressure to squeeze out the material is exerted via a liquid present around the material in the container.

In particular when using extrusion for metals, there is a practical limitation in that that the pressure required for this is dependent on the extrusion ratio. This is due to the ratio of the cross-sectional sizes of the material determined before and after extrusion.

Even with relatively easily machinable metals, a high extrusion ratio can only be achieved by using excessive achieve high pressures on the material and in the container. The manufacture of containers with such pressures to be able to withstand, however, is difficult and expensive.

The invention provides an extrusion molding apparatus which obviates these difficulties.

The invention provides an extrusion apparatus for extrusion of metals, which allows that at least some of the force to extrude the metal through an extrusion die through friction generating Application of the metal to a passage delimiting surface parts a part to be moved is applied to the mold j so that the frictional resistance of the passage delimiting surface parts causes the metal to be pressed out through the mold.

The friction-generating system can be stationary with respect to the extrusion die by the loading of the metal Ren part are effected, the contact surface of the stationary part on the metal is smaller than that of the movable Partly, so that the frictional resistance of the surface parts of the moving part delimiting the passage opposite the metal predominates and this is therefore pressed out by the mold. That of the surface parts delimiting the passage supplied metal can be a solid rod or such a rod or also in powder form.

In conventional mechanical or hydrostatic extrusion determined the size or quantity of the workpiece or material that could be introduced into the pressure vessel

extruded strand producible in an extrusion process. The cross-section size of the workpiece is determined by the the predetermined working pressure of the pressure vessel achievable press-strand ^ ratio limited. An increase in length of the workpiece is therefore only possible by increasing the length or the amount of the starting material with a corresponding increase Extension of the pressure vessel receiving the starting material achievable, but with the difficulties and The cost of manufacturing the container increases.

The extrusion device according to the invention allows a continuous supply of material.

Such a device is characterized according to the invention by first and second, mutually delimiting a passage and parts movable relative to one another in the longitudinal direction of the passage, by means of a part relative to the second part fixed, protruding into the passage and blocking this stop part, through at least one initially the Stop part from the passage leading Preföformoffnung and by means for the continuous supply of extrusion material to one remote from the stop member

- 5-

• part of - 5 - *: '"': ... .,, Passage limiting Passage where in the the

Area portion of the movable part on the stop part is greater than that of the stationary part, so that in the Passage introduced material through the frictional resistance of the surface parts of the first part delimiting the passage is movable in the direction of the stop part and can be squeezed out through the mold opening.

In an advantageous embodiment of the invention, the extrusion mold is characterized by an endless one Grooved wheel, -by a part of the groove length covering and with this a passage delimiting shoe, by a stop projecting from the shoe into the groove and blocking the passage at one end, the wheel opposite the shoe is rotatable in the direction of the stop, by at least one arranged first of the stop Die opening and by means for supplying extruded material to the end of the remote from the stop Passage, so that the extruded material located in the groove by frictional forces in the direction of the stop can be carried along and can be squeezed out through the mold opening. The die opening can be in the Face 'of the stop formed sin. In another embodiment, the stop and the die opening are solid

/ JIf-

is formed in the surface of the shoe before the stop. In the former case, several can in the end face of the stop Mold openings can be formed, and in the latter case several mold openings can be formed in front of the solid stop be formed in the surface of the shoe. In any case, the mold openings can through in seats provided for this purpose used mold inserts be formed.

Several shoes can be operatively connected at mutual distances be arranged with the groove.

The applicant's German Offenlegungsschrift P 19 61 265 relates to an extrusion apparatus in which compressive pressure is applied to the extrusion material, through which the material is conveyed into an area in front of the front surface of a tool, which in turn is moved in such a way that the material in this area is subjected to an additional compression pressure the effect of which, combined with the compression pressure present in the material, moves the material through a tool associated mold opening is pressed out.

In a preferred embodiment used in the mentioned patent application described a device

rotatable tool holder with the Tool protrudes in the form of a projection. The tool holder is driven about an axis running transversely to the end face carrying the projection, so that the Projection moved on a circular path, with its front side on the extruded material located in front of it Exerting pressure. A continuous compression pressure applied or maintained therein. That in front of the front of the ledge Material located in this area is subjected to an additional compression pressure, below that with that in the material Maintained compression pressure combined effect the material through a tool or projection associated mold opening is pressed out.

The device according to the invention can be used for feeding the extruded material into the area of the end face of the Use tool holder in a device of the type described in the aforementioned patent application.

In the embodiment of the present invention having a rotatable wheel, the can be moved along the groove Press material by means of the in the patent application mentioned

descriptive rotatable tool additionally processed be, this being arranged in a bore in the shoe so that it is close to its end face Face of the stop of the groove is freely opposite.

Further features, details and advantages of the invention emerge from the following description of exemplary embodiments with reference to the drawing. Show in it:

Fig. 1 is a partial sectional view of an inventive Extrusion device,

Fig. 2 is a disassembled oblique view of the device shown in Fig. 1,

3 shows a modified embodiment of that in FIGS. 1 and 2 arrangement shown,

Fig. H is a sectional view of a further embodiment of the device according to the invention,

FIGS. 5 to 9 oblique views of modifications of the device according to FIG. 4,

Fig. Io is a partial sectional view of a third embodiment of the device according to the invention and

11 is a sectional view along the line λ XI in Fig. Io.

The extrusion device shown in FIGS. 1 and 2 has a wheel 1 rotatably seated on a shaft 2. A groove with a square cross-section is milled into the circumferential surface of the wheel 1, thus forming a square surface of revolution running around the axis of the wheel. A shoe k can be placed snugly on the circumferential surface of the wheel 1. A stop 5 protruding from the underside of the shoe k has a cross section complementary to that of the groove 3 and protrudes into the latter so that it forms a sliding seal therein. In the stop 5 a passage 6 is formed. A chamber 7 formed in one piece with the shoe 4 is connected to the circumferential groove 3 of the wheel 1 via a bore 8. A sealing block 9 formed at the stop 5 opposite the end of the underside of the shoe ¹ J protrudes into the groove 3 of the wheel 1 with a sliding sealing contact. A material Io for extrusion is pressed through the bore 8 of the chamber 7 and fills the space below the shoe h between the sealing block 9 and the stop 5.

- Io -

- Ιο-

4g

ongoing, part of the groove 3 Russian.

To press in the material Io from the chamber 7 into the Groove 3 can be a plunger in the bore 8 of the chamber 7 to be available. After the compression of the material contained in the chamber 7, the piston is withdrawn and the Chamber 7 further material supplied, for example from each a continuous caster. Otherwise, the material can also be used intermittently in powder form Plunger or continuously fed by screw conveyors.

The wheel 1 is moved in the direction of the arrow 11, that is to say in FIG. 1 driven clockwise. That under the shoe ^! in the Circumferential groove 3 located material Io is thereby through his Frictional resistance against the walls of the groove 3 in the direction of the stop 5 is carried along. This is how it arises in the material Io in the groove 3, a pressure under which the material is pressed out through the passage 6 in the stop 5 will. The rotation of the wheel 1 also causes the material to pull out of the bore under transverse shear forces 8 of the chamber 7 is discharged so that a continuous extrusion process takes place. That while turning the wheel

- 11 -

- 11 -

1 material discharged from chamber 7 is continuously replaced by supplying further material to chamber 7.

In the case of powdery material, the pressure exerted on the same in the groove 3 causes the material to be compressed. The material is further compressed when it is pressed out through the passage 6, so that a solid extruded strand is obtained receives.

The groove 3 in the circumference of the wheel 1 forms together with the Shoe 4 has a passage limited by four walls. Those formed by the side walls and the bottom of the groove 3 Walls move continuously towards the stop. In contrast, it is through the bottom of the shoe 4 formed fourth wall stationary. As already indicated above, the three moving walls lead the groove the material Io due to its friction in the direction of the stop 5 with. The material slides through the the bottom of the shoe 4 formed along the fourth stationary wall. Are the coefficients of friction for everyone four walls are the same, the stationary wall formed by the underside of the shoe 4 is the same as that by the Bottom of the groove 3 exerted frictional resistance, so that

- 12 -

the material ¹ is carried along by the frictional resistances on the two side walls of the groove 3 in the direction of the stop 5. The force acting on the material in the direction of the stop 5 is thus gTsich

2.1.wk,
wherein

1 = the length of the part of the groove 3 located under the shoe 4 in the circumferential direction, in which the material to be pressed is located,

w = the width or height of the side walls of the groove 3 and

k = the shear strength of the 7 \ x pressing material.

The expression 2.1.w.k. given force must result in a load PA on the face of stop 5,

P = the pressure required to extrude the material and

A = the cross-sectional size of the stop 5,

which in turn corresponds to that of the circumferential groove 3

- 13 -

In the case of a groove 3 with a square cross-section

2 '■'

A = W and thus PA = Pw, from which the conditions in extrusion

ρ 2.1.w.k = Pw results.

This results in

2

CL Zx. X

Y = 2k = the yield point of the material. It follows

- P w = _γ

This expression allows the calculation of the various dimensions of the device described above for the Extrusion of a specific material.

An example is the extrusion of copper with a

Assuming a yield point of 3 t per square inch (47.5 kp / mm), the use of a wheel 1 with a circumferential groove of square cross-section with a side length of 12.4 mm and a stop 5 with a passage of 1.905 mm

- 14 -

gives a pressure transmission ratio of about 55: 1 what

2 requires an extrusion pressure of about 157 kgf / mm.

thats why

1 _ 157
2 "F ■ ΤΪΤ75

- 157 * 12.7
5775

1 = about 415 mm.

If a shoe 4 is used that extends over approximately a quarter of the circumference of the wheel 1, then the result is a required diameter of the wheel of about 21 inches (533 mn

Fig. 3 shows an arrangement for the extrusion of continuous Lichem rod material. The arrangement in Fig. 3 is similar that shown in Figures 1 and 2, and £. : Ie parts are marked with the same reference numerals.

In the embodiment shown in FIG. 3, there is none on the shoe 4 Chamber 7 with the bore 8 is provided. The circumferential groove 3

- 15 -

of the wheel 1 is material 11 in continuous strand or Rod shape fed. The material 11 is continuously carried along in the groove 3 under the shoe 4 to the stop 5, and the front end of the strand of material 11 is continuously pressed through the passage 6 in the stop 5. With this arrangement, no feed pressure is required for the material strand 11. Such an arrangement is suitable in particular for the extrusion of powdery material, which is then introduced into the groove 3 with continuous ramming or by means of a screw conveyor can be. Material feed under gravity is also possible in this case, but with devices appear expedient to ensure a free flow. At the beginning of operation with a new material becomes powdery s Material may not be carried away immediately by the moving surfaces. If necessary with some Afterwards, the particles compact themselves in such a way that their frictional resistance becomes effective. With solid material, such as the strand 11, a roller for pressing the material into the groove can be provided immediately in front of the shoe 4 be.

The device shown in Fig. 4 has the same basic shape as that shown in Fig. Ί and 2, with the same parts are again designated by the same reference numerals. the

- 16 -

The device has a rotatable wheel 1 seated on a shaft 2, in the circumferential surface of which a circumferential groove 3 is formed. On the outer surface of the wheel 1 there are two shoes 4 in full contact. On the underside of both shoes 4, a stop 5 is formed in each case, which protrudes into the circumferential groove 3 of the wheel 1. In each seat 7 formed in front of the stop 5, an extrusion mold 6 is inserted, which opens into an outlet 8 passed radially through the shoe h. When the device according to FIG. 4 is in operation, a strand of material 9 is continuously introduced into the circumferential groove 3 under the two shoes 4. The wheel 1 is driven in the direction of the arrow Io, that is, in the counter-clockwise direction. The walls of the circumferential groove 3 exert a frictional tensile resistance on the two strands of material 9, as a result of which they are carried along in the groove 3 under the shoe 4 in the direction of the stop 5. This creates a pressure in the material located below the respective shoe in the courage 3, under the effect of which the front end of the material strand 9 is pressed out by the die 6. The extruded strand emerges radially through the passage S concerned.

Although only two shoes 4 are shown in FIG depending on the circumferential length of the wheel 1, several shoes

- 17 -

be used. For example, three shoes can be distributed around the wheel 1 at a mutual angular distance of 120 °. In a fabrication facility and a plurality of wheels 1 can be arranged on a common shaft 2 and each be provided with a plurality of shoes ¹ I. An arrangement of shoes that are diametrically opposed to one another allows the forces acting radially inward on the bearing of the wheels due to the compression of the material at the stops to be compensated.

As shown in Fig. ¹ J shown, a single mold insert 6 can be k in each shoe, be present. Otherwise, several mold inserts can also be used in each shoe 4. FIG. 5 shows an embodiment in which two mold inserts 6 are inserted one behind the other in front of the stop 5. In FIG. 6, four smaller mold inserts 6 are installed in a group arrangement in front of the stop 5. The use of mold inserts with a non-circular passage is also possible. The mold insert 6 shown in FIG. 7 has a rectangular passage running parallel to the end face of the stop 5, the length of which depends on the width of the circumferential groove 3. The mold insert 6 shown in FIG. 8 has a perpendicular to the end face of the stop 5

- 18 -

rectangular. Passage 11. This arrangement allows the use of a longer passage than the arrangement according to Fig. 7. Fig. 9 shows a core mold insert 6 for manufacture of hollow strand material.

In the embodiments according to FIGS. 1 and 2 tzw. 3 can stop 5 each have several passages ί, which are optionally formed in the form of inserts in the stop Seats are used.

The extrusion device shown in partial views in FIGS. 10 and 11 also has a wheel 1 with a groove 3 formed along the circumference. A shoe 4 is in close contact with the circumferential surface of the wheel. A stop 5 protruding from the underside of the shoe H protrudes into the circumferential groove 3 of the wheel 1. A rotatable mold holder 13 is inserted into a bore 12 which extends radially through the shoe 4 in front of the stop. The mold holder 13 has a projection 15 on the lower end face 14. A mold insert 16 is inserted into the end face 14. In front of the stop 5, a guide part 17 with a wedge-shaped lower part 18 and a cylindrical attachment 19 is inserted into the groove 3.

- 19 -

In operation of the device shown in Fig. Io and 11, the wheel 1 rotates relative to the fixed shoe ^ l in the direction of the arrow 2o, that is, in the counter-clockwise direction (Fig. Lo). The walls of the circumferential groove 3 of the wheel 1 exert a frictional resistance on the material 21 contained therein. The rotation of the wheel 1 thus conveys the material in the direction of the stop 5 of the shoe k ₃ , the guide part 17 deflecting it to the lower end face Ik of the mold holder 13. This creates a uniformly effective pressure in the material 21 located below the mold holder 13 in the groove 3. When the mold holder 13 is rotated in the direction of the arrow 22 in FIG. 11, the projection 15 migrates on its underside through the material 21 located in the groove 21 the pressure uniformly prevailing in the material 21 causes the material to be pressed out through the mold insert 16.

In the embodiments described, the correct seating of the stop part 5 in the groove is not decisive. If there are gaps, some material will leak through them, in the case of processing

- 2o -

- 2ο -

of strand-like material, however, the emerging material then consists of the outer skin of the strand, the Separation of the skin from the finished extruded strand can even be advantageous if the material supplied has surface defects. The groove does not necessarily need to be right-angled or triangular cross-section. So the side walls of the groove, instead of being parallel to each other to stand, run at a square to each other, so that a groove with a trapezoidal cross-section is formed.

- 21 patent claims

Claims (1)

Protection claims 1. Extrusion device characterized by first and second parts (1 or H) which delimit a passage (3) between one another and are movable relative to one another in the longitudinal direction of the passage, by a stop part (1 or H) which is fixed relative to the second part and which protrudes into the passage and blocks it ( 5)> through at least one die opening (6) leading out of the passage and initially arranged on the stop part and by means for the continuous supply of extruded material (lo) to a part of the passage which is remote from the stop part, the surface portion of the passage delimiting the the stop part to the movable part (1) is larger than that of the stationary part (4), so that the material introduced into the passage can be moved in the direction of the stop part through the frictional resistance of the surface parts of the first part delimiting the passage and can be squeezed out through the mold opening . - 22 - 2. Stran ^ pressing device, in particular according to claim 1, characterized by a wheel (1) provided with an endless groove (3), by a part of the groove length covering and with this a passage limiting shoe (*!), By one of the Shoe protruding into the groove and blocking the passage at one end stop (5) 3 , the wheel being rotatable with respect to the shoe in the direction of the stop, through at least one die opening (6) arranged first of the stop and through devices (7, 8) for supplying extruded material to the end of the passage facing away from the stop, so that the extruded material located in the courage can be carried along by friction resistance forces in the direction of the stop and can be squeezed out through the mold opening. 3. Apparatus according to claim 2, characterized in that the groove (3) has a uniform cross-sectional shape determined by a surface of rotation around the axis of the wheel over its entire length. M. Device according to claim 2 or 3, characterized in that that the groove (3) is formed along the circumferential surface of the wheel (1). - 23 - 5. Device according to at least one of claims 1 to 4, characterized in that the passage through his entire length has constant cross-sectional shape. 6. Device according to at least one of claims 1 to 5, characterized in that the die opening (6) is formed in the end face of the stop part (5). 7. Apparatus according to claim 6, characterized in that several in the end face of the stop part (5) Mold openings (6) are formed. 8. Device according to at least one of claims 1 to 5, characterized in that the stop part (5) is massive and that the mold opening (6) initially the stop part in a part on which the stop part is attached, or protrudes, is formed. 9. Extrusion device according to claim 8, characterized in that in the part of which the stop protrudes, or to which it is attached, several extrusion mold openings are available. 10. The device according to at least one of claims 6 to 9, characterized in that the pre-mold openings through in seats (.7) in the parts provided for this purpose (4 or 5) used die inserts (6) formed are. 11. The device according to claim 2 or 3 »characterized in that that in operative connection with the groove (* J) several shoes (4) are arranged at mutual distances. 12. The device according to claim 2 or 3j, characterized in that that first the stop part (5) a device (15) for processing the in the groove (3) of the wheel (1) located material (21) having form holder (13) is provided, which in a closed Circular path is movable or drivable, whereby the first located on the stop part in the groove Material by means of the processing device (15) an additional pressure load can be exerted, under which by the rotation of the wheel in the in the Groove contained material generated pressure combined effect the material through the die opening (16) is eatable. - 25 - 13. The device according to claim 2 or 3, characterized in that in a the shoe ( ¹ I) first the stop (5) penetrating in the groove (3) opening bore (12) a rotatable mold holder (13) with one on its end face (I ¹ I) protruding projection (15) and a porous insert (16) inserted therein, which can be driven by means of devices provided about an axis running transversely to the front side of the projection, so that the front side of the projection rises when pressure is exerted the material located in the area of the end face in the groove can be moved in a circular path, whereby the material located in front of the front side of the projection is subjected to an additional pressure load, under the pressure generated by the rotation of the wheel in the material contained in the groove combined effect, the material can be squeezed out through the mold insert. 14. The device according to claim 13, characterized in that that for the deflection of the material located in the area of the end face of the stop (5) in the groove (3) - 26 - (21) to the front side (1 * 0 of the mold holder (13) a guide part (17) is provided, which tapers away from the end face of the stop part with a wedge-shaped lower part (18) rests on the bottom of the groove and one seated on it with its end face in the middle of the end face of the mold holder Contains attachment (19), so that the protruding projection on the end face of the mold holder during rotation of the mold holder is movable around the end of the attachment of the guide parts.