DE2949587A1 - Cold extrusion of billet into tube - is carried out using anvil axially aligned with power pad in die - Google Patents

Abstract

The cold extrusion includes feeding the billet into a die cavity while the cavity is open, closing one end of the die cavity and disposing an anvil in the opposite end to define an annular space between the anvil and the die cavity wall. The annular space is closed and pressure applied against a selected area of the billet sufficient to cause the billet to commence extrusion about the anvil and to fill the die cavity. The volume of the annular space between the anvil and die cavity wall into which the billet is extruded is increased while maintaining a uniform second pressure against the billet in opposition to the flow of the metal, the magnitude of the second pressure being less per unit area than the first pressure whereby the metal flows uniformly in the course of the extrusion.

Description

Method and device for cold extrusion

of metal billets The invention relates to a method for Old extrusion of Netali billets with a die into tubular products by a single continuous movement. It also has a device for carrying it through this procedure is the subject.

The extrusion of metals by reciprocating motion without The state of the art is the heating of the metal before deforming. This shaping process However, they have several disadvantages, including tool breakage difficulties and the cross-sectional constraints of the part that can be made from a particular metal billet should be shaped belong.

In a typical extrusion process, the metal billet is made into held in a die cavity. A die or anvil is inserted into the phtrix cavity introduced and held in place with the formation of an annular space in between, while the billet is pressed under pressure over and around the anvil, resulting in one Extrusion of the billet in and closing from the annulus between the die cavity and the anvil. In other embodiments the anvil is moved relative to a stationary die cavity, whereby the Billet out of the die cavity through the annulus between the anvil and the wall of the die cavity is extruded through it.

It has already been established that tool breakage, in particular a rupture of the anvil, can occur when the anvil is against the die cavity is misaligned by more than 0.0013 cm per cm, for example. This wrong one Alignment can occur as a result of the anvil wobbling and / or defects be caused in the metal billet. For example, there can be hard spots in the Billets and / or air pockets lead to incorrect alignment of the anvil, sufficient to break the anvil. As a result, experts have accepted that a reduction greater than about 70 * by extrusion, like the retrograde Extrusion, is no longer feasible in practice. The "reduction" (in%) is defined by the following equation: Reduction + B x 100 Gl 1, A where: B = is the cross-sectional area, in centimeters, of the bore formed in the extruded product and A = the cross-sectional area of the billet in cm before the start of the extrusion process.

Accordingly, the "reduction" is a measure of the size of the hole in the extruded product, produced by a single piece with a certain cross-sectional area is to be expected.

Previously, it was common practice to find a product with a proportionate large bore wished to use a billet that had a corresponding, relatively had a large cross-sectional area.

An issue that has to do with the extrusion process of manufacture of a product is decisive compared to metal cutting, represents the savings in metal. Experts take into account that that the production of the billets from which parts are to be formed is economical must be, both in terms of the method used and in terms of on saving metal. For this reason, it is desirable that the billet has as small a diameter as possible in a certain process, so that the billet is sheared from, for example, a standard size metal wire can be made by a conventional shearing process to make metal losses as small as possible to keep. In contrast to this is sawing or milling or another Separation process, as this results in a considerable waste of metal. It it can be seen that the desire to have a billet with the smallest possible diameter to use comes into direct conflict with the generally accepted rule, that a billet is no more than about 70% of its original cross-sectional area can be reduced.

Around a starting stick with the smallest possible cross-sectional area to be able to use and thus to realize the necessary economic efficiency, associated with the choice of continuous casting as a shaping process, Certain known extrusion processes include multiple stages in which the billet reduced several times, d. H.

is extruded, with each successive extrusion the diameter of the product is increased by an amount that is within the previously accepted reduction limit is. These multiple "push" procedures increase admittedly the costs of the process and thus the costs of the product formed.

The invention as characterized in the claims lies the object is based on a cold extrusion process and a cold extrusion device to provide, through which reductions of over 100% are possible and thereby to make the manufacture of extruded products cheaper.

This is achieved according to the invention by a single "pushing process, whereby a force is formed against the billet subjected to extrusion and is maintained, which acts against the direction of the extrusion force, and wherein the flow of metal is controlled in the course of extrusion. It has found that the opposite force exerted on the extruded Product is exercised, the product appears to solidify with respect to the extrusion device, so that the extruded product is relatively strong at one end within the annulus between the anvil and the die cavity and is held at the opposite outer end by a member, the one Counter-extrusion force exerts the function on the product while it is being molded seems to have a lateral support bushing for the anvil around which the billet is extruded.

Tool breakages are negligibly small due to the invention, and even at production speeds between 30 and 40 products per minute. Furthermore, the product has excellent physical properties, including good dimensional tolerances.

The invention enables reductions of over 112% to be achieved.

The controlled force opposing the extrusion force is lower than the extrusion force. In the method according to the invention for cold extrusion of a metal billet is the extruded portion of the metal billet to begin with imprisoned in an annulus formed by the wall of the die cavity and the concentrically arranged and axially aligned anvil is determined while a Force applied to the outer end of the extruded product which is opposite to the extrusion force and which is the extruded Reinforced product compared to the extruder.

With the invention, the cross-sectional area of the bore in the extruded product is maximized. Furthermore, the extruded product is im Reinforced during the extrusion process.

The invention is exemplified below with reference to the accompanying drawings explained. These show: FIGS. 1 to 3 partially reproduced and partially cut the sequence of operations of an embodiment of the device according to the invention; Fig. 4a, 4b and 4c together in partial reproduction a top view of a partially cut, partially broken away embodiment of the device according to the invention, wherein the Device is shown in its open position for tool change; Fig. Fig. 5 shows, in partial reproduction, a plan view of the partly cut and partly broken right end of the device according to FIG. 4c; Fig. 6 in partial reproduction a plan view of the device partially broken away and partially sectioned according to FIG. 4b, specifically in the closed position during extrusion; Fig. 7 shows a view of a section along the line 7-7 according to FIG. 4a; Fig. 8 in a schematic Representation of a hydraulic control device for controlling the inventive Contraption; 9 shows a schematic detail reproduction of part of the control device according to Fig. 8; and FIG. 10 is a block diagram of an electrical device for control the operation of the device according to the invention.

In Figs. 1 to 3, the sequence of operations of an embodiment is that of the present invention Device shown schematically.

The representations in these figures show, also schematically, the steps of the procedure to be used.

In detail, in the embodiment according to FIGS. 1 to 3, a tool collar 9 is provided, which has a tool or a die 10, which is supported by a shrink ring 12 is surrounded. By the die 10, a cavity 14 is defined, in which at one end 16 a reciprocating punch 18 is arranged, which is the end 16 of the cavity 14 closes.

A metal billet 20 is disposed within cavity 14 and the other end 22 of the cavity 14 is closed by a pressure chuck 24, which consists of a sleeve through which an axial bore 26 is defined. Within the bore 26 has a reciprocable anvil 28 disposed thereon. The pressure lining 24 is provided with an annular shoulder 32 which is designed so that it is within of the end 22 of the cavity 14 is received, so that this shoulder 32 and the The front end 30 of the anvil 28 is near the end 22 of the die cavity 14 are located. A collar 34 surrounds the pressure liner 24 and, as will be seen below it will enable the controlled exertion of pressure on the pressure chuck 24, about their position with respect to the die 10 and the engagement of the shoulder 32 on the to be able to optionally customize extruded product.

In Fig. 1, a magazine 36 is shown schematically in which several metal billets 20 'are in a position to be successively in the Die cavity 14 can be given, which will be described in more detail below is.

In the embodiment according to FIG. 1, the anvil 28 is arranged in a stationary manner and held in place by a first force represented by arrow A. Furthermore, the pressure chuck 24 is in the position in which the annular space 40 between the anvil 28 and the inner wall 42 of the die cavity 14 closes, by a Force, which is shown by the arrow B moves. In Fig. 1, the punch is 18 also shown as if a pressing process by a force caused by the Arrow C is shown, which force exerted on the punch 18 is initiated is to move the billet 20 into the annulus 40 between the anvil 28 and the die cavity wall 42 to press.

In Fig. 2 the punch 18 is moved further into the die cavity 14, so that the billet 20 has been partially pressed around the anvil 28. Be it notes that the annular shoulder 32 of the pressure chuck 24 is held in contact and pressed is against the outer end 44 of the extruded billet 20, the abutment the shoulder 32 and end 44 of the stick 20 maintained by a force which is reproduced by the arrow B ', which force is exerted on the collar 34 which in turn transmits the force to the pressure chuck 24. In the course of the Extrusion, the force on the pressure chuck 24 is set to a value which is less than the extrusion pressure, but becomes a relatively large one Maintain value contrary to the extruded thickness.

After completion of the extrusion process, as shown in Fig. 3, the pressure chuck 24 moves into the retracted position with respect to the die 10, the punch 18 is withdrawn, as is the anvil 28, around the extruded one To drop product 48 by gravity through a detector 46, on the Function will be discussed below.

The device is then able to carry out a further working cycle to start.

In Fig. 4a, 4b and 4c, an embodiment of the device is for Implementation of the method described is shown.

Figures 4a, 4b and 4c give top views of the top of the device again and show several plates 50, 52, 54 and 56 resting on appropriate Means, such as the stand 57 (see. Fig. 7) are arranged. The plates 50, 52, 54 and 56 are preferably rectangular and lie in perpendicular planes, the run parallel to each other substantially, the connection between the Plates 50, 52, 54 and 56 are made by several bars 58, 59, 61 and 63 (similar to Fig. 7), those in exactly matching openings in the relevant corners of plates 50, 52, 54 and 57 are added.

In Fig. 4a to 4c only the spar 58 is shown, but it is from Fig. 7 immediately recognizable that at each of the opposite corners cer rectangular Plates 50, 52, 54 and 57 essentially identical spars 58, 59, 61 and 63 are provided are. The spar 58 is representative of each of these spars, so that the description of the spar 58 for understanding the structure and function of each of these spars is sufficient. In the embodiment shown, the end 60 of the spar protrudes 58 through the end plate 56 and is externally threaded for receiving a suitable nut 62 is provided. The spar 58 is concentric with a first Bearing component 64 is provided which extends along substantially the entire length of the Holmes 58 extends between end plates 50 and 56. The concentric components 64 extend through the intermediate plates 52 and 54. The end of the Holmes 58 (not shown), opposite end 60, protrudes through the plate 50 in the same way as the end 60 through the plate 56, and is with a Threaded to receive a nut provided, such as the nut 62 at the end 60 of the Holmes 58.

The device is assembled by using the spars 58, 59, 61 and 63 are inserted into the four corners of the rectangular plates 50, 52, 54 and 56, the concentric sleeve members S4 extending through the plates 52 and 54 and their opposite ends near the inside 72 of the plate 56 and the inside 74 of the plate 50 are arranged to the minimum distance between the end plates 50 and 56 to be determined and fixed. When the spar 58 and the associated, concentric Component 64 are in the correct position, the nuts on the opposite one Ends of Hosme 58 tightened so that the end plates 50 and 56 against the ends of the component 64 due to the tension of the spars 58, 59, 61 and Press 63 to hold the assembly together.

A sleeve 66 is around the bearing component 64 in the space between the plates 54 and 56 are provided with rings 68 and 78 between the ends of the sleeve 66 and the plates 54 and 56 are arranged. The sleeve 66 and their corresponding Counterparts on the bars 59, 61 and 63 ensure the minimum distance between plates 54 and 56.

The plate 52 is displaceable on the component 64. The movement of the Plate 52 along component 64 to the right is bounded by a sleeve 96, which surrounds the bearing component 64 in the space between the plates 52 and 54. Between The ends of the sleeve 96 and the plates 52 and 54 are rings 70 and 76 arranged.

As mentioned, the plate 52 is opposite along the bearing component 64 the fixed end plate 50 displaceable.

At this end a sliding bush 102 is provided on the bearing component 64, which the plate 52 in one of its corners, as mentioned above, receives. Similar Slide bushings are provided at the other corners of the plate 52 (val. Fig. 7).

This sliding movement of the plate 52 enables the devices to be opened that hold the tool collar 9 in place, which is shown in the Embodiment is achieved by piston / cylinder units 82 and 83, of which only the unit 82 is shown in Figure 4a. The cylinder 84 of the piston / cylinder unit 82 is attached to the inside 74 of the plate 50 by means of a rod head 88, at one end to the cylinder 84 and at its other end to a fork head the end plate 50 is attached.

The piston rod 90 of the piston / cylinder unit 82 is via a Clevis 92 connected to one side 94 of plate 52. Preferably the second is Piston / cylinder unit 82 provided on the opposite side of the device, so that an evenly applied force is guaranteed to the position the plate 52 compared to the plate 50 to change. As mentioned, this is movement the plate 52 is provided to the device for tool change and / or maintenance work to be able to open. When the plate 52 is moved to the right as shown in Fig. 6, the tool collar 9 is clamped in place for an extrusion process.

When the plate 52 is moved to the rightmost position, i. H. the apparatus is closed for an extrusion process are one or more Spacer sleeves 100 are provided, which the tubular member 64 in the space between surround plates 50 and 52. One or more of these spacer sleeves, or at If additional spacer sleeves are required, they are removable so that, if it is desirable, move plate 52 to the open position, d. H. in the direction to the left in Fig. 4a and 4b, along the component 64 space is available in which the Plate 52 can be moved. The same detachably attached sleeve is replaced, when the plate 52 is in the closed position.

As can be seen from Fig. 4b, the middle plate 54 is with a removable, first tool collar holder 108 is provided on its surface 110. The holder 108 is releasably attached to surface 100 by means of bolts 112. The holder 108 is provided with a recess 114 on its outer surface 113. At the surface 116 of the Opposite plate 52 and holder 108 is a second tool collar holder 118 featured, which is detachable with the plate 52, for example Bolt 120 is connected. The outer surface 119 of the second holder 118 is provided with a Recess 122 is provided, which is opposite the recess 114 in the holder 108. The tool collar 9, which consists of the die 10 and the shrink rings 12 and 126 (Fig.

1 and 6), is releasably attached between the holders 108 and 118. to for this purpose the outer surface of the shrink ring 126 is inclined 128 and 130, which are formed so that they are in the recesses 114 and 122 fit.

In particular, the surface 128 has a different angle than that Surface 130 and the geometry of the recesses 114 and 122 is chosen so that they record only the associated inclined surfaces 128 and 130, so that it is practically impossible is, the tool collar 9 in the device in a wrong or in a reverse Position. They also represent the angular relationship between the recess 114 and the associated surface 128 and the recess 122 and the associated Surface 130 a precise alignment of the tool collar 9 in the recesses 114 and 122 safe, and thus an exact parallel alignment of the tool collar 9 opposite the plates 52 and 54. Furthermore, through the recesses 114 and 122 and the corresponding surfaces 128 and 130 a precise concentric arrangement of the tool collar 9 achieved with respect to the remaining parts of the device, as described in more detail below is made clear.

The holder 118 is also provided with a channel 132 through which a magazine is formed which holds a plurality of billets 202 in place for insertion into the die 10 to be introduced. The legs 20 'can be known by any suitable means Facility to be given in the magazine.

As mentioned above, the die 10 shown is with a Cavity 114 provided, which extends through the entire Ma- trize 10 extends and is open at both ends. The hollow space is according to the invention 14 is provided with a first cylindrical portion 136, the cross section of which is the length is essentially the same, and with a second portion 138, the Cross section is larger than the cross section of section 136. According to a preferred In the embodiment, the section 138 is relatively short compared to its length of section 136.

In the embodiment shown in FIGS. 4b and 6, the device is provided with a punch 140, the with its outer end 142 within the die cavity section 136 is received in a reciprocating manner. The punch 140 is in a sleeve 144 stored in the ring plate or

is disposed on the tool collar holder 118 and extends therefrom, to be received in an opening 148 extending through plate 52. Inside the plate 52, the sleeve 144 is received by a further sleeve 146, which in turn fits into an opening 148 extending through plate 52. This results in the concentric arrangement of the punch 140 with respect to the ring plate 118 of the tool collar 9 and the plate 52 maintained.

The free end of the punch 140 is an enlarged piston head 150 formed, which in turn is essentially surrounded by a bush 152, in turn within an externally threaded end 153 of the Tool holder 154 is housed. The end 153 of the tool holder 154 is closed by an internally threaded cap 156, the inside a hollow cylindrical punch support 458 is slidably received, the is in turn detachably connected to the plate 52 by bolts 160. This is the piston head 150 of the punch 18 is slidable and axially aligned with the die cavity 14th stored. The support 158 is at its outer end with a Externally threaded to receive a screw cap 162 which has a back 159 has, as a stop for the optional adjustment of the path of the punch 18 serves in its retracted position, d. H. to the left according to Fig.

4a.

The enlarged portion 138 of the die cavity 10 is formed so that the reduced diameter annular shoulder 32 on the die cavity 14 facing end of the pressure chuck 24 fits exactly into it. As mentioned above, the pressure chuck 24 is provided with an internal bore 26 in which the anvil 28 is reciprocally added. When the front end 30 of the anvil 28 is in the front position, so on the left in Fig. 6, so protrudes at the In the illustrated embodiment, the end 30 of the anvil 28 from the pressure chuck 24 into the cavity section 38. In this position, between the end of 30 of the anvil 28 and the wall of the cavity section 138, an annular space 42 is defined.

As also mentioned above, the pressure chuck 24 is of a Collar 34 worn, as shown in Fig. 4b, with a thread in one End 166 of a hollow cylindrical piston 168 is attached, which in turn is reciprocally received in a housing 170 which has one end 172 having a reduced diameter secured in plate 54. The inner diameter of the reduced diameter end 172 of housing 170 is axially aligned with a central bore 173 through the Thickness of the plate 54 therethrough and with a central bore 175 through the tool collar holder 108 through so that the piston 168 with respect to these aligned bores 173 and 175 is reciprocable. The opposite end r of the housing 170 is closed by a cap 174. In the housing 170 are Connections 176 and 178 for the flow of hydraulic fluid into the annular spaces 180 and 182, respectively, at opposite ends of the enlarged portion 184 of the anvil 168 is provided, which enlarged portion 184 is sealed against the housing 170 through a seal 186. The end 166 of the piston 168 is similar sealed by a seal 188 with respect to the end 172 of the housing 170. That opposite end 190 of piston 168 is with respect to cap 174 i by a Seal 192 sealed.

The cap 174 is still at its free end with a collar nut 194 provided, which in turn by an annular stop provided with an internal thread 196 is included, which acts as an adjustable limitation of the retraction movement of the Anvil 28 is used, as can be seen below.

The outer end of the anvil 28 is expanded to form a piston head 198. The piston head 198 is fastened in a bushing 200, which in turn is in a with an externally threaded end 201 of a cylindrical tool holder 202 received is. The end 201 of the tool holder 202 is internally threaded Surrounding sleeve 203, which in turn is slidably received in an axial bore 204 which is provided in a piston 168 so that the anvil 28 is axially movable is opposite to the piston 168 and the pressure chuck 24, which helps the To keep the end 30 of the piston 28 concentric with the piston 168.

The tool holder 202 comprises a substantially cylindrical one middle section 216 extending from the rearward end 205 of the hollow piston 168 protrudes to be releasably received in the front end 218 of a piston 220. Of the Tool holder 202 is also provided with a longitudinal slot 224 one Side. A cover 222 for the tool holder is slidably arranged and surrounds a central portion 216 of the tool holder 202. The cover 222 is provided with a suitable opening so that when the cover is rotated 22 the opening in the cover can be made to close with the slot 224 align to expose the interior of the hollow tool holder 222. In the hollow A plurality of spacers 226, 228 and 230 are provided inside the tool holder 202. When the anvil 28 is removed or replaced with a tool of a different size or the position of the anvil 28 relative to the piston 220 is to be changed removed spacers 226, 228 and 230 or specially selected spacers and spacers of other lengths are used for this purpose, the spacers 226, 228 and 230 through slot 224 and the aligned opening in the cover 222 can be removed.

As shown in Figs. 4c and 5, the force to move the anvil 28 is and move forward, applied by a piston / cylinder unit 219 incorporated in the Plate 56 is attached. As can be seen from Fig. 5, the plate 56 is with a central hole 232 provided. The bore 232 is also provided with a sleeve 234 which surrounds the piston 220 which extends through the bore 232. "Chevron" seals 236 provide a sufficient seal as the piston 220 slides through plate 56. A sealing ring 238 is provided on side 72 of plate 56 and surrounds the piston 220. The rear end 240 of the piston 220 is provided with a Piston head 242 is provided, which is slidably mounted within a hollow cylinder 244 with a sliding seal in between which is influenced by seals 246 and 248 will.

In this way, the hollow cylinder 244 is in two expandable chambers 245 and 247 divided, each of which is arranged at a different end of the piston head 242 is.

The cylinder 244 includes a cylindrical housing 250, which with one end 252 is secured in plate 56. The housing 250 extends from the plate 56 backwards, that is to the right in FIG. 5, and is on its rear side 254 closed by a plate 256. Inside the end 254 of the cylinder 244 a further hollow cylinder 258 is provided, which is concentric and in axial alignment is arranged opposite the cylinder 244 and defines a chamber 259.

The cylinder 258 is further provided with a cylindrical sleeve 260, in which a reduced diameter piston portion 262 is received extending rearwardly from piston 220 to slidably within the sleeve 260 to be received. Seals 264 surround the piston section 262 and provide the seal between the outer surface of the piston section 262 and the sleeve 260.

The plate 256 is provided with a first connection 266, which is connected to a chamber 259 communicates so that hydraulic pressure flowing through the port 266 is applied to pressurize the chamber 259 and the piston portion 262 to the left in FIG. The plate 256 is with another connector 268 provided, which has a bore 270, a line 272 and a bore 274 with the chamber 245 of the cylinder 244 on the left side of the piston head 242 according to Fig. 5 communicates. Another connection 256 with a much wider opening is in the wall of cylinder 244 at a rearward location; H. right in 5, with respect to the fully retracted position of the piston head 242 and communicates with a chamber 247 of the cylinder 244.

The force to move the punch 18 back and forth (on the anvil 28 opposite end of the device) delivered by a device which is substantially the same as the device described above is described in connection with the reciprocating movement of the anvil 28, so that the foregoing description of the piston / cylinder device that reciprocates Movement of the anvil 28 accomplished is sufficient for understanding the means by which the ram 18 is reciprocated. In Fig. 4a that part of the device is shown that of the same device in Fig. 4c and Fig. 5 corresponds, as indicated by the reference numerals provided with a prime made clear.

A schematic representation of the hydraulic control for provision a programmed actuation force for the various working organs of the present Apparatus is shown in FIG. The various working bodies of the present Device are by and large by a main hydraulic circuit, the one provides relatively high pressure and a secondary hydraulic circuit, the one provides relatively low pressure, actuated. In the main hydraulic circuit of the The illustrated embodiment provides pumps 300 and 302 driven by a motor 304 are driven, a pressure fluid that is passed through corresponding filters 306 and 314 and corresponding regulating valves 308 and 310 to a manifold 309 is funded. The line 309 communicates with a first rotary valve 312, which is assigned to the piston / cylinder unit 219, which provides the motive force for the anvil 28 delivers. The line 309 is still with a second rotary valve 312 ', which is associated with the piston / cylinder unit 219', which the Movement force for the reciprocating movement of the punch 18 provides.

The pressure fluid in the main circuit becomes a reservoir 311 Recirculated via an overpressure regulating valve 316.

The pumps 300 and 302 suck pressure fluid from the reservoir lines 315 and 317 respectively. The hydraulic fluid in the main circuit supplies the Driving force for the pistons 220 and 220 ', around the punch 18 and / or the anvil 28 to move forward and / or hold stationary against the extrusion pressure.

In automatic operation, it is desirable that the piston 220 with rapid forward movement until the anvil 228 is in position for the extrusion process has passed. When the anvil 28 is in the extrusion position approaches, it is desirable that the forward motion slow down considerably and that the movement of the anvil 28 into its extrusion end position with a relative low speed takes place. In the illustrated embodiment, this is double the speed of the piston 220 is achieved by first pressurized fluid into chamber 259 at the rear end of the small diameter Piston portion 262 is supplied.

The action of this pressure fluid on the rear side 257 of the piston section 262 ensures rapid advancement of the piston 220 until the piston section 262 has moved completely out of chamber 259. Then the pressure fluid into a considerably larger inner chamber 247 within the cylinder 244 on the Back of the piston head 242 released. At this point the is approaching Anvil 28 in its extrusion position. Due to the relatively larger surface area of the Piston 242 on the back 241 guides the pressure fluid into the chamber 247 has been admitted, to the fact that the piston 220 is relatively slow advanced until the anvil 28 reaches its extrusion position Has. The forward movement of the anvil 28 is provided by the front side 311 of the tool holder 216, which is attached to the piston 220, stopped by attack of the Rear side 313 of the anvil stop 196 (see. Fig. 4c).

The pressure created by pumps 300 and 302 sets the The high pressure section of the hydraulic system represents kg / cm2, with a pressure of about 211 kg / cm is aimed for, which generates a working pressure of 75 tons. It can be seen that other, similar, relatively high pressures can be used depending on the circumstances of the extrusion process.

The secondary hydraulic circuit has a lower pressure 2, namely about 105 kg / cm; it is also shown in FIG. The secondary hydraulic circuit includes a motor 322 which drives a pump 324 through which the pressurized fluid flows a filter 326 is conveyed to a manifold 328. The pressure in the secondary Hydraulic circuit serves several purposes, including providing a pilot pressure, that used to operate some of the ones used in the control system's hydraulic circuits Regulating valves is used. The hydraulic fluid of the secondary system is also used to operate the pressure chuck 24, as well as for opening and closing the tool collar clamping device, in detail the pressure fluid is from of pump 324 through filter 326 and through line 350 to manifold 328 conveyed, which has a return line 352 through which the pressure fluid to reservoir 311 and then to pump 324 to complete the circuit.

In the distributor 328 a pressure relief valve 354 is arranged, which over Lines 350 and 352 connected to facilities r is through which the maximum pressure within the secondary circuit is regulated.

According to Fig. 9, the chambers 180 and 182 of the cylinder 170 for to supply the reciprocating movement of the pressure chuck 24 with pressure fluid, In the distributor 328 a rotary valve 356 is provided, the inlet 358 with the Line 350 is connected. The outlet 360 of the rotary valve 356 is through a conduit 362 connected to a pressure relief valve 364. The outlet 368 of the pressure relief valve 364 is connected by a line 370 to the connection 378 in the cylinder 170, in order to produce a force which the pressure chuck 24 on its engaged position loaded with the die 10.

It should be noted that the pressure relief valve 364 is regulated manually and a bypass 372 containing a regulator valve 374.

It is important that if one during an extrusion process Force against the pressure chuck 24 is exerted. by extrusion, a pressure build-up takes place within the chamber 182 on the rear side of the piston 168. This pressure build-up is passed on through line 370 to pressure relief valve 364. As the regulating valve 374 prevents the backflow of the pressure fluid around the bypass 372, the throughput the pressure fluid from the chamber 182 behind the piston 168 by the adjustment of the pressure relief valve 364 is regulated. By setting the pressure relief valve accordingly 364 it is thus possible to produce a pressure that is developed to accommodate the To hold pressure chuck against the force of the extrusion process.

As can be seen, this pressure is chosen to be sufficient is to exert a counterforce against the part subjected to extrusion, which the extrusion sen subject to the Tool collar, the plate 54, etc. solidified, so that the part has a lateral support for the anvil 28 forms when the pressure chuck 24 engages in an extrusion process subject metal moved backwards. The force to keep the pressure chuck 24 in to bring its rearward position after completion of the extrusion process, will applied by the hydraulic fluid flowing into the front chamber 180 of the cylinder 170 is fed through line 376, which is connected to line 350 by a Rotary valve 356 communicates. An electromagnet 378 adjusts the Valve 356 by selecting the direction of flow of the pressure fluid through valve 356 secure.

Although the specific embodiment of the device disclosed in Figures 4a, 4b and 4c is shown, no pressure lining on the punch side of the die 10, it should be noted that Figs. 8 and 9 show the manner in which such a pressure chuck 24 'can be provided and controlled. Essentially the control of the pressure chuck on the stamp side is essentially identical with the control of the pressure chuck on the anvil side, so that the description of the Hydraulic circuits to control the pressure chuck on the anvil side is sufficient for an understanding of the way the print lining is on the stamp side is controlled. Equivalent organs of the control system for the pressure feed the stamp side are indicated by reference numerals provided with a prime.

As mentioned above, the opening and closing of the tool chuck also controlled by the secondary hydraulic circuit. 9 is the inlet 379 of a rotary valve 380 via a line 382 to a distribution line 350 tied together. The outlet 384 of the rotary valve 380 is via a controlled regulating valve 386 and a line device 388 with the rear chambers 390 and 392 of the piston / cylinder units 82 and 83, which, as indicated above is to ensure the movement of the platen 52 to the tool collar chuck to open and close.

The outlet 394 of the rotary valve 380 is through a controlled regulator valve 396 and a line 398 with the front chambers 400 and 402 of the piston / cylinder units 82 and 83 connected. The rotary valve 380 thus opens and closes of the tool collar clamping device is achieved by adjusting the flow direction with the slide 380 the hydraulic fluid is selected. Solenoids 404 and 405 attached to the slide 380 are provided, are used to control the actuation of the slide 380. To complete the circle, the rotary valve 380 is through an outlet conduit 406 connected to the return line 352.

As mentioned, it is desirable in the movement of the anvil 28 that the anvil 28 is first moved rapidly forward into its extrusion position that however, the movement of the anvil 28 is to be slowed down just before its End position reached for the extrusion process. As also mentioned above is, the rapid forward movement of the anvil 28 is caused by the supply of pressure fluid reaches, for example, from 211 kg / cm2 into the chamber 259 in the cylinder 258 the valve 312. The valve 312 is a center spring loaded double Solenoid valve with blocked connections and is in operation due to its size relatively slow.

For example, it is desirable that after the anvil 28 has its front Has reached the limit position of the movement, the valve 312 is closed, i. H. is pushed to the position with the connections blocked to reduce the pressure in the Chamber 247 open right and thus the anvil 28 in one to maintain a stationary position during extrusion. The relatively slow one Operation of valve 312 results in a small but undesirable delay between the time the anvil 28 is positioned and the beginning of extrusion. In addition, leakage after valve 312 can result in a Backward movement of the anvil 28 and interruption of the extrusion to lead. Therefore, the hydraulic circuits shown in Fig. 8 are also with a slow forward control loop that operates at all times during an extrusion cycle maintain pressure within chamber 247 using low flow rates receives. This circuit has a rotary throttle valve 410, the inlet 412 of which is connected to the main hydraulic circuit via a line 414. The rotary valve 410 is actuated by a solenoid 416. The outlet 417 of the rotary valve 410 is closed via a throttle valve 418 and a line 421 with connection 423 connected to the interior of the chamber 247 on the rear side of the piston head 242.

A regulating valve 425, which is arranged in the line 421, prevents the flow back through the line 421. When the system is closed, the rotary valve 410 initially by supplying pressure medium through the connection 266 to the chamber 259 of cylinder 258 is actuated and remains actuated until the cycle is completed. on in this way, pressurized fluid is continuously supplied to the chamber 247, the is sufficient to cause the anvil 28 to move slowly forward and hold the anvil 28 in place regardless of the operating speed of valve 312. It can be seen that this slow forward movement of the anvil 28, however, is initially superimposed by the action of the pressure fluid within the chamber 259 of the cylinder 258 until the piston portion 262 exits the chamber 259 Has.

In connection with the rapid forward movement of the piston 220 it should be noted that while the piston 220 by the pressurized fluid in the chamber 259 is rapidly advanced, a rapidly increasing volume change in the chamber 247 takes place. This rapid change in the size of the volume of the chamber 247 gets called a "vacuum" emerges which questions the desired rapid advancement of the piston would be provided if no adjustment to such a change in volume were foreseen. According to the invention, the adaptation to this change in volume takes place in that the Chamber 247 through connection 276 to a hydraulic fluid reserve container 420 is connected, which ensures a supply of hydraulic fluid to the chamber 247 without substantial inhibition of the forward movement of the piston 220. to for this purpose the port 276 is relatively large. The connection between the connection 276 and the container 420 takes place through a line 422 in which a Check valve 424 is arranged, which the flow of pressure fluid to Chamber 247 allowed and the flow out of chamber 247 only allowed if the check valve 424 is overridden.

It can also be seen that such a flow of the pressure fluid out of chamber 247 is desired when piston 220 is being withdrawn target. Oversteering the check valve 424 to prevent such an outflow to allow is achieved by hydraulic pressure applied to the check valve 424 is exercised via a line 426 which is connected to a rotary valve 428 connected between lines 350 and 352 of manifold 328. Of the Rotary valve 428 is operated by an electromagnet 430 so that when a suitable signal of the rotary valve 428 pressure fluid through the line 426 the check valve 424 can flow to override the check valve 424 and the flow of pressurized fluid from the chamber 247 to the container 420 possible.

A rapid forward movement of the punch 18 is similar how the rapid forward movement of the anvil 28 is achieved. This is done by the Rotary valve 312 ', the structure and function of the rotary valve described above 312 is identical. In addition, a check valve 424 'is provided between the chamber 247 'on the back of the piston 220' and a hydraulic fluid reservoir 420 'is switched. The check valve 424 'is overridden by pressure fluid reached, which can flow through a line 424 'which is connected to a rotary valve 428 'which is actuated by an electromagnet 430'. the Function and functioning of the corresponding organs described above can be recognized without further ado.

In a preferred embodiment the hydraulic control is provided with a visual pressure indicator, which has several positions to a allow visual indication of the pressure at several points in the system. As As shown in Figure 9, position # 2 is via line 440 with a line 370 connected to an indication of the pressure within chamber 182 of the cylinder 270, and thus the display of the pressure that is applied to the extrusion process subject product is exercised. Position no. 6 is via line 442 connected to the outlet of rotary valve 428 for an indication of the pressure within of the secondary hydraulic flow. Position # 5 is about one Line 444 connected to front chamber 180 in cylinder 170 for display of the rearward pressure exerted on the pressure chuck 24. Position # 4 is connected by line 446 to line 376 'to to enable an indication of the pressure exerted on a pressure liner on the stamp side the die 10 is exercised when a such pressure lining used will. Position no. 3 is connected to the main hydraulic circuit via a line 448.

When operating the device shown in the individual figures a plurality of relatively thin cylindrical billets 20 are loaded into the magazine 132 given. In response to a suitable electrical signal, the electromagnet 404 is actuated, to open the valve 380 to prevent the flow of pressurized fluid to the chambers 390 and 392 of the piston / cylinder units 82 and 83 to enable the Tool set clamped in the correct position between plates 52 and 54 will.

The tool collar 9 is held in this position until another one Signal is given to the solenoid 405 to operate the valve 380, so that the direction of flow of the pressure fluid through the valve 380 and into the Chambers 400 and 402 of the piston / cylinder units 82 and 83 is changed to the Tool collar clamping device to open. As soon as the tool collar 9 is in the correct position Position is clamped, an electrical signal is sent to the electromagnet 416 and 440 submitted.

The solenoid 440 opens the valve 312 and enables the flow of pressurized fluid through port 266 to chamber 259 into cylinder 258, whereby the rapid forward movement of the anvil 28 begins. While the As piston 220 advances, a "vacuum" is created in chamber 247, the pressurized fluid from container 420 and pulls check valve 424 toward chamber 247.

When the valve 312 is opened, the electromagnet opens at the same time 416 the valve 410 to control the flow of pressure fluid from the main hydraulic circuit through valve 410 to chamber 247. The valve 410 remains so long open until the anvil 28 retracts as previously described.

Also at the beginning of the forward movement of the anvil 28 is simultaneous the solenoid 378 actuates the valve 356 to open so that pressurized fluid via line 370 to chamber 182 at the rear of the Piston 168 can get, whereby the forward movement of the pressure chuck 24 begins.

The pressure chuck 24 moves forward in contact with the Die 10 and is held against it by the pressure from the secondary hydraulic circuit, which is controlled by valve 368 and its bypass 372. When the pressure chuck 24 comes into contact with the die 10 or another point on its path of movement reached, a suitable signal is generated to actuate the electromagnet 440 ', to start the forward movement of the punch 18. It can be seen that the The anvil side of the die cavity 14 is closed by the pressure chuck 24 and the anvil 28 is. When the punch 18 moves forward, its front end comes into contact with a billet 20 and presses the billet 20 into the die cavity 14. Through further forward movement of the punch 18 becomes the billet extrusion process 20 initiated, which extrusion process is continued until the punch 18 at When moving forward, for example, an electronic eye happens, whereupon a a suitable electrical signal is generated to actuate the electromagnet 441 ', to reverse the direction of movement of the punch 18.

The signal from the electronic eye that is the front limit of the Movement path of the stamp 18 perceives, will continue to about 30 to 50 milliseconds delayed, fed to an electromagnet 441 to reverse the movement of the anvil 28 to begin. When the backward movement of the anvil 28 and punch 18 has started the solenoids 430 and 430 'are actuated to the valves 428 and 428' to operate to pressurized fluid to open the check valves 424 and 424 ' to supply the same and to enable the printing liquid is dispensed into containers 420 and 420 'in chambers 247 and 247'. Also will at the same time as the backward movement of the anvil 28 begins, a suitable one electrical signal fed to electromagnet 378 to change the direction of flow to change the pressure fluid through the valve 356 so that the chamber 180 in the Cylinder 170 is pressurized to reverse the movement of the pressure chuck 24 to initiate.

While the chuck 24 and anvil 28 are being withdrawn, the extruded product is withdrawn from the die cavity 14, whereby it is still on the anvil 28. The pressure chuck 24 reaches the rear end the trajectory when the surface 313 on the collar 196 is in contact with the surface 311 of the tool holder 216 comes.

The anvil 28 continues to move backward, thereby removing the product is stripped from the anvil 28. The stripped product falls by gravity goes down and passes the detector 46 to give a signal for the next cycle of operation to create.

In an embodiment for extrusion, in which the inventive The method and the device according to the invention were used, became billets Sheared from a wire made from a cold-pressed quality steel A1S1-1008. The single ones Billets were cylindrical, 3.23 cm long and 1.587 cm in diameter and a weight of 50 g. These billets underwent a conventional pretreatment, including annealing and cleaning, subjected and with phosphate and molybdenum sulfide powder. The pretreated billets were around the Extruded around the end of a cylindrical anvil that is 1.681 in diameter cm at a rate of 30 to 40 extrusions (Clubs) per minute and with the described, automatically working Contraption. The anvil was placed inside a cylindrical die cavity, which was 2.18 cm in diameter, leaving an annulus between the anvil and the die cavity was 1.5171 cm2 in cross-sectional area.

The extruded product had this process the dimensions of a cylindrical beaker two inches long, the one outer Had a diameter of 2.159 cm and an inner diameter of 1.681 cm, so that a cross-sectional area of the bore of 2.21009 cm2 ("B" in Eq. 1) resulted. the Cross-sectional area of the billet before extrusion was 1.97886 cm2 ("A" in Eq. 1). Hence, according to Eq. 1 the reduction about 112%.

The anvil 28 became stationary in this process with a pressure of held for about 75 tons while the punch 18 advances with the same pressure became. The pressure chuck 24 was initially in the closed position with the die 10 2 held at a pressure of about 105 kg / cm. The pressure relief valve 356 was regulated, d. H. manually adjusted to allow the flow of the pressurized fluid with the existing extrusion force to a back pressure of about 105 kg / cm2 during of extrusion led. This back pressure was initially increased on a relative basis great value as the punch puts the billet in contact with the anvil and the pressure chuck brought, and then decreased, when the pressure chuck is in the retracted position by a greater pressure exerted by the extruding billet, was pushed back.

The back pressure exerted by the pressure chuck was in everyone Trap big enough to hold the extruding billet firmly in concentric orientation with the anvil so that the extruded product has a lateral support for the anvil and enabled its alignment when the pressure chuck was withdrawn. It can be seen that during extrusion the metal des Knüppels in the plastic state essentially only in the annulus between the end of the anvil and the die cavity wall passes and that at least one Part of the extruded product solidifies before leaving the die cavity, so that this end of the extruded product is firmly in a concentric arrangement too the die cavity and the anvil.

The breaking strength of the billet was about 2,742 kg / cm2 and the of the extruded product about 5,624 kg / cm2. The yield strength of the billet was about 1,687 kg / cm2 and the 2 of the extruded product about 4,499 kg / cm Other steel alloys, such as A1L1 1018, 1020 and 4027, have also been used with success in the above Way extruded.

All of the extrusion described above was done with a single "Bump" reached, d. H. with a working cycle of the device in which the billet is deformed only once to obtain the extruded product.

In addition to the usual savings with extrusion compared to the machining production of a product from a metallic one Material are achieved, enables the method according to the invention or the invention appropriate Device the production of a certain product from a wire as a material, thereby reducing the cost of the billet. Furthermore, the inventive Method and device according to the invention, the production of a specific extruded product with a single "push" as opposed to multiple "Bumps" that were previously required. In addition, tool breakage is minimal, d. H. it is practically non-existent if the method according to the invention or the device according to the invention are used.

In addition to the usual forces that act on the metal in a conventional Acting extrusion process, it has been found that the pressure against the Metal is exerted against the extrusion pressure, the metal additional "work" feeds. The exact effects of this on the flow of the metal are not known, but it seems to have a beneficial effect after the improved ones Judging products. In any case, it appears that the movement, i.e. H. the flowing of the metal is controlled during extrusion in the sense that the Metal is not released to be pressed out of the die in an uncontrolled manner, as is the case with the prior art, rather the metal, as indicated, pressed out of the die under constraining forces in order to enable a reduction, such as it has so far not been possible to achieve it with a single "push". In particular, cares the back pressure automatically for the continuous change in the dimensions of the Product in the course of the extrusion process.

Modifications of the preferred embodiment shown and described of the invention are possible. For example, instead of the pressure fluid other energy sources can be used. Furthermore, the coming to the application Manpower can be varied to the required to be machined Amount of a certain metal or alloy to be adjusted.

Claims (6)

Method and device for cold extrusion of metal billets Claims Process for cold extrusion of metal billets with a die to tubular products by a single continuous movement, g e k e n n z e i c h n e t through the following process steps: Insertion of the billet (20) into the die cavity (14); hydraulic load on a first link (18) in Closed position with a first open end (16) of the die cavity (14); hydraulic loading of a second member (28) in a partially closed position with the second open end (22) of the die cavity opposite the first end (16) (14), which second link (28) is arranged substantially coaxially to the first link (18) and with a force (A) opposite to the force (C) of the first link (18) can be acted upon; hydraulic loading of a third link (24) in the closed position with the portion of the second end (22) of the die cavity (14) passing through the second link (28) is not closed, which third link (24) is coaxial to the first link (18) and coaxial and concentric to the second link (28) is arranged; Applying sufficient hydraulic pressure to the first link (18), during the closed position of the second (28) and the third (24) member with the second end (22) of the die cavity (14) maintained is so that the Saüppel (20) substantially fills the die cavity (14); with continued pressure on the first member (18) to move the same in the die cavity (14) control of the hydraulic fluid flow rate for the third member (24) depending on the hydraulic pressure, the third Member (24) loaded into its closed position with the die cavity (14), independently from the extrusion speed of the billet (20) to a substantially constant one To create pressure against the billet (20) and against the direction of extrusion and the retreat of the third member (24) from its closed position with the Allow die cavity (14) at a rate that does not decrease the total forces acting on the stick (20) lead to a value that is smaller is than the value that the billet (20) in the area subjected to deformation is maintained in a flow condition to extrude the billet (20) from the die cavity (14) out and around the second link (28) while a sufficient pressure against the leading end of the extruded billet (20) is maintained in order to increase its deformability significantly and the billet (20) being extruded between the die (10) and solidifying the third member (24) during extrusion; and stripping of the extruded billet (20) from the second link (28). 2. Process for cold extrusion of metal billets with a die to tubular products by a single continuous movement, g e k e n n z e i c h n e t through the following process steps: Insertion of the billet (20) into the die cavity (14); Moving a first link (18) into the closed position with a first open end (16) of the die cavity (14) and in contact with the stick (20) under hydraulic pressure; Moving a second link (28) in a partially closed position with the second opposite the first end (16) open end (22) of the die cavity (14) under hydraulic pressure; Move a third link (24) in closed position with the remainder of the second End (22) of the die cavity (14) under hydraulic pressure, so that the second (28) and the third (243 link) the second end (22) of the die cavity (14) essentially closes; Applying a first force (C) to the first limb (18) to tile the metal of the billet (20); Exercising a second (A) and a third (B) force on the second (28) and third (24) link, each of which is sufficient to stop the movement of the stick (20) from the second end (22) to prevent the die cavity (14) when the billet (20) is in the die cavity (14) is converted into the flow state, with continued exposure to the first (C) and second (A) force the third force (B) is maintained, until the metal of the billet (20) passes into the flow state and the die cavity (14) essentially fills; Control of the hydraulic fluid flow rate depending on the pressure of the hydraulic fluid source (300, 302), so that the third force (B) is reduced to a predetermined value that controls the movement of the billet (20) from the die (10) prevents the reduced force (B ') is kept essentially constant, regardless of the metal flow rate, until the metal flow in the billet (20) is complete, where the metal flow is controlled by the deformation of the billet (20) in the die (10) is increased; and then removing the forces (A, B ', G). 3. The method according to claim 1 or 2, g e k e n n z e i c hn e t through such a shaping speed of the billet (20) that at least one billet (20) weighing at least 50 grams in 2 seconds or less taking Cold worked conditions that affect essentially all billets. 4. Device for performing the method according to one of the claims 1 to 3, characterized in that the first member (18) is axial to the Die cavity (14) is aligned and the first end (16) of the die cavity (14) closes, the second member (28) aligned axially to the die cavity (14) and having a forward end (30) which is the second end (22) of the die cavity (14) partially closed, the third member (24) axially to the die cavity (14) is aligned and has a forward end that joins the second end (22) of the die cavity (14) partially closes, the second (28) and the third (24) member together substantially closing the second end (22) of the die cavity (14), respectively hydraulic devices are provided to apply a second force (A) to the second Member (28) and a third force (B) on the third member (24) to exert it to load in the closed position with the second end (22) of the die cavity (14), a further hydraulic device is provided to generate a first force (C) exercise the first link (18) to engage the first link (18) with the stick (20) in To bring contact and the stick (20) between the first (18), the second (28) and to press the third (24) link so hard, that the stick (20) flows and. the die cavity (14) fills, each independent control devices for the first (C), the second (A) and the third (B) force are provided with a Control device that acts on the pressure that the hydraulic device that the third force (B) exerts on the third link (24), responds and the third force (B) maintains a predetermined value sufficient to allow the metal to flow from the die cavity (14) and the subsequent, during the first Force (C) is maintained regarding the flow rate of the hydraulic fluid of the third member (24) controls so that the third force (B) to a predetermined Value (B ') is reduced, which allows a controlled movement of the third link (24) with respect to the first member (18) ensures, the reduced force (B ') im is kept essentially constant, regardless of the speed of the metal movement of the billet (20) until the flow of the metal (20) is complete, which changed Force (B ') is sufficient to significantly increase the deformation capacity. 5. Device for performing the method according to one of the claims 1 to 3, indicated by a die cavity (14), the longitudinal axis of which is open at the opposite ends (16 and 22), one of which is first end (16) of the die cavity (14) has a cross-sectional area which is smaller than the cross-sectional area of the second end (22) of the die cavity (14); by a punch (18) inserted in the first end (16) of the die cavity (14) is arranged to be movable to and fro; by an elongated anvil (28), whose forward end (30) within the enlarged second end (22) of the die cavity (14) and is arranged aligned on its longitudinal axis to have a ring opening therebetween (40) to form through which the billet (20) is pressed, which Annular opening (40) from the extension of the first end (16) of the die cavity (14) is offset radially outward; by a pressure chuck (24) which has an annular Section which is arranged in the ring opening (40) and closes the same; by a hydraulic fluid source (300, 302); by a piston / cylinder unit (82, 83); by a device that frictionally engages the piston / cylinder unit (82, 83) connects to the pressure chuck (24); by a device for connecting the hydraulic fluid source (300, 302) with the piston / cylinder unit (82, 83); by a control device, through which the drainage of the hydraulic fluid from the piston / cylinder unit (82, 83) controlled as a function of the pressure in the piston / cylinder unit (82, 83) will; by a device through which the piston / cylinder unit (82, 83) an essentially constant, opposite to the extrusion of the billet (20) Force builds up when the billet (20) with the pressure chuck (24) during extrusion of the billet (20) is in contact, which force, regardless of the extrusion speed of the billet (20), is constant and essential to the deformability of the Billet and for strength of the extruded portion of billet (20) outside of the die cavity (14) contributes. 6. Apparatus according to claim 4 or 5, characterized in that g e -k e n n z e i c h n e t that a magazine (36) for the billets (20 ') and a device for feeding same in die cavity after retraction of the first link or punch (14) are provided.