EP0747144A1 - Process for the hot extrusion of metal with the active assistance of friction forces, and a hydraulic extrusion press for carrying out this process - Google Patents

Process for the hot extrusion of metal with the active assistance of friction forces, and a hydraulic extrusion press for carrying out this process Download PDF

Info

Publication number
EP0747144A1
EP0747144A1 EP94906412A EP94906412A EP0747144A1 EP 0747144 A1 EP0747144 A1 EP 0747144A1 EP 94906412 A EP94906412 A EP 94906412A EP 94906412 A EP94906412 A EP 94906412A EP 0747144 A1 EP0747144 A1 EP 0747144A1
Authority
EP
European Patent Office
Prior art keywords
container
ram
cylinder
billet
extrusion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP94906412A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0747144A4 (en
Inventor
Valery Nikolaevich Shcherba
Vladimir Nikolaevich Alferov
Alexandr Kuzmich Svinarev
Vladimir Nikolaevich Danilin
Vladimir Sergeevich Razumkin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0747144A4 publication Critical patent/EP0747144A4/en
Publication of EP0747144A1 publication Critical patent/EP0747144A1/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/21—Presses specially adapted for extruding metal
    • B21C23/211—Press driving devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/21—Presses specially adapted for extruding metal
    • B21C23/218—Indirect extrusion presses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C31/00—Control devices, e.g. for regulating the pressing speed or temperature of metal; Measuring devices, e.g. for temperature of metal, combined with or specially adapted for use in connection with extrusion presses

Definitions

  • the invention relates to the processing of metals by pressure, specifically to a process for the hot extrusion of metal with the active assistance of friction forces, and to a device for implementing it, and may be used to obtain rods, bars and shapes used in the aircraft industry, civil engineering, motor industry, etc.
  • the conventional, known process for the hot extrusion of metal comprises the following operations: heating the billet in a furnace, feeding it into a container and extruding the billet through the channel of the die while simultaneously moving the ram and the container.
  • the article obtained is transported onto a cooling table, and the remaining discard is separated from the die and placed in the waste.
  • a process for pressing metal and alloys which comprises heating a metal billet, placing it in a container, extruding it and removing the article and the discard (compare Patent No. 2675125).
  • the container and the ram are moved with various combinations of their speeds, but excluding the case when the speed of the container exceeds the speed of the ram.
  • the container is stationary and only the ram is moved, extruding the billet through the channel of the die.
  • a process is realized which is termed direct, and the articles obtained have a high-grade surface.
  • the billet is moved relative to the container, with the result that there are formed on the contact surfaces of the billet reactive friction forces which are directed in the opposite direction to the metal outflow.
  • This circumstance requires the application of substantial energy expenditure in order to overcome them.
  • the nature of the metal flow in the direct process of extrusion is marked by a high degree of unevenness, which may be the reason for the appearance of internal defects in the product.
  • the container and the ram are moved simultaneously at identical speeds.
  • Such a process is termed indirect. In this instance, there is no need to overcome friction forces between the container and the billet, with the result that substantially less energy expenditure is required to implement this process.
  • the articles obtained have no internal defects, but the extrusion requires billets with a turned external surface, and this requires sizable additional costs.
  • the unevenness in the metal flow remains although it decreases by comparison with the direct extrusion process.
  • the unevenness in the metal flow leads to nonuniformity in the structure and physico-mechanical properties along the length and over the cross-section of the articles.
  • the pressing process described above is characterized by the presence of a significant speed gradient at the site of deformation origin, what limits the maximum outflow rates when pressing a broad range of alloys. For the same reason, significant tensile stresses, which can lead to the appearance of cracks, arise on the surface of the articles in the channel of the die.
  • a device is known (see US Patent 2675125) which can be used to extrude metal by means of direct, indirect or mixed methods (in the process of extrusion operation one method is being changed to another).
  • the device consists of a container, which is mounted on a frame with the possibility of reciprocating movement along its longitudinal axis, and a movable crosspiece to which there is rigidly attached a plunger of a main cylinder which is mounted in a stationary fashion on the rear cross beam.
  • a movable crosspiece Mounted on the movable crosspiece are two cylinders for moving the container, the plungers of which are rigidly attached to the container.
  • Mounted on the front cross beam are return cylinders for moving the container, the plungers of which are also rigidly attached to the container.
  • a ram which enters the container in the process of extrusion, while a hollow ram which is mounted in a stationary fashion on the front cross beam is arranged on the other side of the container, likewise in a fashion coaxial therewith.
  • the inner spaces of power hydraulic cylinders are connected via a distribution box to high-pressure and low-pressure mains.
  • the heated billet is raised by a feed mechanism to the axis of the press. With the crosspiece idling, it is pushed into the container.
  • a pressing process employing the direct method is started (for example).
  • the return cylinders for moving the container are closed, and fluid at high pressure is supplied to the main cylinder, while the container cylinder is connected to a low-pressure mains. Under the action of the ram, the billet starts to be extruded through the die.
  • the press is switched to the indirect method. For this, the return cylinders of the container are connected to the low-pressure main, while the container cylinders are closed. At this instant, the speeds of the pressing crosspiece and the container become equal, and the indirect pressing process starts.
  • the process is stopped. Using the cylinders for moving the container, the discard is extracted from the container and detached. The article is removed and the cycle can be repeated.
  • the extruding device for only the direct or indirect processes. It is also possible for them to be combined otherwise in the course of the extrusion process.
  • the present device does not permit extrusion with the active assistance of friction forces. For this reason, the articles are obtained with a low level of mechanical properties and an uneven distribution of them along the length and over the cross-section of the articles. It is not possible on this device to achieve limiting rates of metal outflow, which reduces the productivity of the process.
  • Extrusion requires the billet to be placed into the container and the latter to be closed, from one side, by a die having a channel corresponding to the profile of the article to be obtained, and from the other one, by a short ram.
  • the die is mounted on the hollow ram. Thereafter, movement of the container and ram is initiated, the speed of the container being higher than the speed of the ram.
  • the reactive friction forces characteristic of the direct process are transformed into active friction forces aimed in the direction of the outflow and facilitating the latter.
  • Using a kinematic coefficient having a value less than its optimum values in the process of extrusion leads to localization of the shear deformation in the boundary layer, which increases the unevenness of the metal flow and reduces the permissible level of the rate of pressing.
  • the device comprises a frame on which are mounted an upper and a lower cross beams (vertical implementation of the press).
  • Mounted on the upper cross beam is the main power cylinder, whose plunger is rigidly attached to the movable crosspiece.
  • Mounted on the lower cross beam are the return power cylinders for moving the crosspiece, the plungers of which are rigidly attached to the latter.
  • An auxiliary cylinder with a plunger is mounted on the crosspiece.
  • the ram with a die block is rigidly attached to the plunger.
  • the container is mounted on the crosspiece with the aid of columns.
  • the hollow ram is mounted with the die on the lower cross beam.
  • the main and return power cylinders are connected via valves to high-pressure and low-pressure mains.
  • the auxiliary cylinder is connected to the low-pressure main via a throttle.
  • the heated billet is fed to the axis of the press and pushed into the container with the aid of the hollow ram and the die. Fluid at high pressure is supplied into the main cylinder, and the crosspiece is lowered together with the container. A pressing-out stage begins, followed by extrusion. At this moment, the speeds of the container and of the ram are identical, and the indirect process of extrusion takes place.
  • the throttle is opened and fluid displaced from the auxiliary cylinder into the low-pressure main.
  • the plunger depression of the auxiliary cylinder takes place, which leads to a reduction in the speed of the ram movement relative to the speed of the container movement.
  • the friction forces of active assistance are induced to the lateral surface of the billet.
  • the discard is detached from the article and removed.
  • the die is mounted on the hollow ram and the cycle can be repeated.
  • the given device permits the process to be carried out using the active assistance of friction forces.
  • the object of the present invention is to provide such a process for the hot extrusion of metal with the active assistance of friction forces, and a hydraulic extrusion press for implementing it which, by virtue of a definite ratio of the speeds of movement of the container and ram, would permit an increase in the productivity of the press and, at the same time, regulation of the distribution of mechanical properties along the length of the finished product.
  • This object is achieved when in a process for the hot extrusion of metal with the active assistance of friction forces, consisting in that a billet undergoing extrusion is preheated and placed in a container from which this billet is thereafter extruded, with the aid of the ram and container, through a die, which determines the shape and geometrical dimensions of the finished article, while moving said container and ram simultaneously, it being the case that in the process of extrusion the container is moved at a speed higher than the speed of movement of the ram, in accordance with the invention the speed of movement of the container exceeds the speed of movement of the ram by approximately 1.05-1.3 times.
  • the ratio of the speeds of the container and the ram may be kept constant.
  • the ratio of the speeds of the container and ram may be varied within the limits of 1.05 to 1.3 times.
  • the speed of movement of the ram may be varied as a function of the variation in the gradient of the temperature of the billet along its length.
  • a hydraulic extrusion press comprising front and rear cross beams rigidly mounted on a frame, a container with the possibility of reciprocating movement along its longitudinal axis, and a crosspiece on which there is rigidly mounted a plunger of at least one main power cylinder whose body is mounted in a stationary fashion on the rear cross beam, and on which there is also mounted in a stationary fashion at least one auxiliary cylinder which is arranged coaxially with the main power cylinder and to whose plunger there is rigidly attached a ram with a die-plate which enters the container in the process of extrusion, while a hollow ram connected to the front cross beam is arranged on the other side of the container, likewise in a fashion coaxial therewith, the inner space of the main cylinder being connected to the high-pressure main and low-pressure main and the inner space of the auxiliary cylinder communicating via a restricting unit with the low-pressure main, in accordance with invention the restricting unit comprises at least one stabilizing cylinder which is a cylindrical body
  • the inner space of the stabilizing cylinder can communicate with the low-pressure mains.
  • the hydraulic extrusion press comprises at least two booster power cylinders, each of which is constructed in the form of a cylindrical body in which there is arranged a plunger, and one of the said elements of each booster power cylinder is attached in a stationary fashion to one of the cross beams, while the other is attached to the crosspiece, and the inner space of each of these communicates with the low-pressure fluid main and the high-pressure fluid main.
  • the hydraulic connection between the inner space of each cylinder, which is hydraulically connected to the auxiliary cylinder, and the corresponding high-pressure and low-pressure mains can contain a valve.
  • each booster cylinder is hydraulically connected to the inner space of the auxiliary cylinder.
  • the hydraulic connection between the inner space of the auxiliary cylinder and the inner space of each power hydraulic cylinder connected thereto can contain a valve.
  • the hydraulic extrusion press can contain an auxiliary restricting unit having a body with holes and fitted with a cover, inside which there is mounted a slide valve which is spring-loaded from the side of the cover and has a through space, whose configuration and geometrical dimensions determine the magnitude of the speed of the mutual movement of the container and ram, hydraulically connected via corresponding holes of the body to the inner space of the auxiliary cylinder and to the low-pressure main, while on the side opposite the spring-loaded one there is mounted a cylinder whose body is rigidly connected to the body of the restricting unit, while a plunger is also rigidly connected to the slide valve, and the inner space of this cylinder is hydraulically connected to the inner space of the auxiliary cylinder, it being the case that the cover on the body of the restricting unit can be mounted capable of axial movement in order to control the magnitude of the preliminary compression of the spring.
  • the auxiliary restricting unit can contain a lead screw attached in a stationary fashion to the end face of the slide valve on the side of the spring, while the cover can have a through hole through which the screw passes with the possibility of controlling their mutual reciprocal movement.
  • the cylindrical body and, correspondingly, the plunger of the auxiliary cylinder can be constructed in a stepped fashion, while the spaces formed by these steps communicate hydraulically between one another.
  • the step of the auxiliary cylinder which faces the plunger of the main power cylinder prefferably to be partly arranged in this plunger and rigidly connected thereto.
  • a billet 1 ( Figures 1,2,4) undergoing extrusion is heated, placed in a cavity 2 of a container 3 and further, by means of simultaneously moving a ram 4 and container 3, extruded through the channel of a die 5 which determines the shape of the finished article (not shown in the figure), which die 5 is mounted on a hollow ram 6.
  • the container 3 is moved at a speed which exceeds the speed of the ram 4 by approximately 1.05-1.3 times.
  • the billet 1 can be heated, for example, in induction furnaces, resistance furnaces and combustion furnaces (not shown in the figure).
  • the temperature range of the heating of the billet 1 is selected as a function of the type of alloy of the billet 1 undergoing extrusion. For example, in the case of heating a billet 1 made from hard deforming aluminum alloys the heating is performed up to temperatures of approximately 300-400°C as a function of the requirements for the mechanical properties of the articles and of the rate of pressing.
  • Heating the billet before extrusion permits a reduction in the resistance to deformation of the material of the billet undergoing deformation. This permits a reduction in the expenditure of energy for the process of extrusion.
  • heating billets renders it possible to increase the level of the mechanical properties of the articles.
  • heating permits an increase in the adhesive interaction between the billet 1 and container 3, which leads to an increase in the friction forces, and this is very important for the process being patented, since in the process under consideration the friction forces between the container 3 and billet 1 play a positive role, increasing the depth of the peripheral metal flow.
  • the billet is fed to the press with the aid of a feeding mechanism 7 and pushed into the cavity 2 of the container 3 of the press.
  • the container 3 has a length such that it is possible for the billet, die 5, and ram 4 to be placed entirely and freely in it.
  • the length of the ram 4 corresponds to that part of the length of the container 3 which is essential for the mutual displacement relative to the billet.
  • the container 3, die 5, and ram 4 can be preheated before pressing in order to reduce the expenditure of energy on the process of extrusion.
  • the preheating temperature is a function of the material of the billet 1 being extruded. For example, it may be approximately 300-400°C in the case of pressing hard deforming aluminum alloys.
  • a stroke of the crosspiece 8 starts to move the container 3 and ram 4 simultaneously towards the die 5.
  • the length of the hollow ram 6 must be equal to the length of the container 3, so that it is possible to withdraw the die 5 from the opposite side of the container 3.
  • the stage of pressing-out the billet 1 begins after the ram 4, billet 1, and die 5 have come into contact. At this stage, the billet 1 occupies the entire volume bounding it. The diameter of the billet 1 becomes equal to the diameter of the container 3. After this, the metal begins to be extruded into the channel of the die 5.
  • the configuration of the channel of the die 5 corresponds to the cross-section of the article to be obtained, but taking account of the thermal expansion of the die 5 as a result of its warming and of a certain shrinkage of the metal after the latter has cooled.
  • the speed of movement of the container 3 and ram 4 must be identical (indirect process of pressing), while in the opposite instance individual parts of the lateral surface of the billet 1 can be displaced onto another part of this surface, since only a part of the billet 1 is in contact with the container 3. This can lead to defects in the articles.
  • the speed V C of movement of the container 3 is increased by 1.05-1.3 times by comparison with the speed V R of movement of the ram 4.
  • the ratio of the speed V C of movement of the container 3 to the speed V R of movement of the ram 4 is conventionally termed the kinematic coefficient K W .
  • a more uniform metal flow guarantees a reduction in the tensile stresses on the lateral surface of the finished articles. These stresses are a fundamental restraining factor in the selection of the limiting rate of extrusion over a whole range of alloys, for example, when extruding hard deforming aluminum alloys. Thus, a reduction in the tensile stresses permits an increase in the limiting permissible rates of extrusion by 2-3 times in the case of hard deforming aluminum alloys. Moreover, such a favorable metal flow produces conditions of a quasistationary metal flow, which permits a reduction in the nonuniformity of the distribution of mechanical properties along the length and over the cross-section of the articles.
  • the material of the billet undergoes in addition not only shear deformations but also a retarding of the axial flow what promotes better processing of the cast structure of the material and an increase in the density of dislocations as well in the general level of the mechanical properties of the articles.
  • the enhancement of mechanical properties of the articles is 10-40%.
  • the effectiveness of the given process depends substantially on the conditions of interaction between the container 3 and billet 1, that is to say on the magnitude of the realization of the active assistance of friction forces.
  • the process of extrusion is conducted up to a specific magnitude of the billet 1, which is termed the discard (which has not been shown in the figures).
  • the height of the discard is basically determined by the instant of the start of the formation of the first type funnel.
  • the ram 4 is withdrawn, the discard is pushed out from the container 3 and, furthermore, separated.
  • the finished article is extracted from the die 5, straightened if necessary and cut to size and put into a storehouse for the finished product.
  • the container 3 can be moved at a constant ratio of the speed V C /V R of movement of the container V C to the speed of movement of the ram V R , which is within the limits of approximately from 1.05 to 1.3.
  • the level of the mechanical properties of an article and the distribution of those properties along its length are influenced by the initial temperature of the billet 1, the rate of pressing and the magnitude K W of the ratio V C /V R of the speeds of movement of the container V C and ram V R .
  • the leading movement of the container 3 permits additional displacement of the peripheral layers of the billet 1, what leads to additional shear deformations in the material being extruded. This, in turn, permits breakup additionally of the cast structure of the billet 1 and, thereby, enhancement of the mechanical properties of the articles.
  • the initial uniform temperature field in the billet can vary.
  • Light heating of the container 3, the die 5 and ram 4 results in a gradual cooling of the billet 1 in the process of extrusion.
  • the temperature of the billet 1 exerts a substantial influence on the process of dynamic recrystallization, and therefore on the structure of the articles being obtained and this, in turn, affects the level of the mechanical properties of the articles.
  • it is necessary to compensate the change in the conditions of recrystallization in the billet by means of varying the magnitude K W of the ratio V C /V R of the speeds of movement of the container V C and ram V R .
  • K W the magnitude of the ratio V C /V R of the speeds of movement of the container V C and ram V R .
  • Heating the billet 1 in accordance with the proposed process when the temperature of the front end face is 1.2-1.5 times higher than the temperature of its rear end face permits an increase of temperature of rear end face of the billet at the expense of the deformation heat being released.
  • processes of heat exchange with the working tools proceed in the billet 1, with the result that the dwell time of the billet 1 in the container must be at a minimum, as far as possible. Consequently, it is most effective to use billets heated in a graduated way along the length in a high-speed process for pressing with the active assistance of friction forces.
  • Heating the front end face of the billet up to a temperature of 0.7-0.9 of the temperature of processing ductility of the metal being extruded permits starting of the process at the required rate of extrusion, and the articles do not have any defects in the form of cross cracks.
  • this temperature is 350-400°C for hard deforming aluminum alloys.
  • the temperature of the front end face of the billet 1 is higher than 0.9 of the temperature of processing ductility of the metal being extruded, defects in the form of cross cracks are formed on the articles in the initial stage. To remove them it is necessary to reduce the rate of pressing significantly, which will also lead to a reduction in the productivity of the process.
  • the temperature of the rear end face of the billet 1 is higher than 0.7 of the temperature of processing ductility of the material being extruded, at the end of the process not all the heat of deformation is compensated, and the billet 1 will begins to overwarm. It is necessary to reduce the rate of pressing in order to exclude the appearance of cracks on the articles.
  • the temperature of the rear end face of the billet 1 When the temperature of the rear end face of the billet 1 is less than 0.5 of the temperature of processing ductility of the metal being extruded, at the end of the process the temperature of the billet 1 decreases. In this case the expenditure of energy on deformation of the billet 1 grows, the capacity of the press is insufficient and the rate of the process drops. This also leads to a reduction in the productivity of the process. Moreover, a change in the temperature of the billet 1 in the process of deformation leads to nonuniformity in the distribution of the mechanical properties along the length of the articles.
  • a change in the rate of extrusion with the aid of a speed governor 9 in the course of the process permits a more delicate reaction to the changes in the temperature field in the billet 1, and thereby permits a constant temperature of the article to be kept with high accuracy at the exit from the channel of the die 5. This provides the possibility of obtaining an exclusively uniform distribution of the mechanical properties along the length of the articles, and increasing significantly the productivity of the extrusion process.
  • the filed process for the hot extrusion of metals with the active assistance of friction forces by inducing friction forces of active assistance to the surfaces of contact of the billet and container, and controlling them in an optimum range permits the implementation of a new process of extrusion with maximum efficiency.
  • the rate of the peripheral flow relative to the central layers of the billet can be controlled within rational ranges by varying the ratio of the speeds of movement of the container and ram in conjunction with selection of the conditions of temperature and rate of the process.
  • the process being patented permits the achievement of high rates of extrusion, and thereby a reduction in the dwell time of the billet in the container within the limits of a minute.
  • Such conditions permit the use, with high efficiency, of billets with graduated heating along the length, which in its turn renders it possible additionally to increase the productivity of the entire process by 15-20%.
  • the hydraulic extrusion press being patented comprises a frame 10 ( Figure 1) on which are mounted a front cross beam 11 and rear cross beam 12 between which the container 3 and crosspiece 8 are mounted, with the possibility of axial reciprocating movement, on guides (not shown in the figure).
  • Power cylinders are mounted on the rear cross beam 12: the main power cylinder, which has a cylindrical body 13 and plunger 14, and return cylinders (not shown in the figure, for the sake of simplicity) .
  • the plungers 14 of the main and return cylinders are rigidly connected to the crosspiece 8.
  • stabilizing cylinder mounted on the rear cross beam 12 is at least one stabilizing cylinder, which has a body 15 and plunger 16.
  • Two or more stabilizing cylinders can be mounted on the press for the purpose of reducing the overall dimensions of the press and in accordance with the technology being used.
  • Two stabilizing cylinders are shown in Figure 1 as a design variant. Also as one of the design variants, it is possible to mount the cylindrical bodies 15 of the stabilizing cylinders on the rear cross beam 12, while their plungers 16 can be rigidly connected to the crosspiece 8.
  • Axial channels 17 communicating with the conduit 18 are constructed in the plungers 16.
  • the conduits 18 connect the inner space 19 of the stabilizing cylinders to the inner space 20 of the auxiliary cylinder, which has the cylindrical body 21 and plunger 22, which are mounted coaxially on the crosspiece 8.
  • the plunger 22 of the auxiliary cylinder has a coaxially mounted ram 4 to which the die-plate, 23 is rigidly attached.
  • a window 30 into which the article being pressed passes, is constructed in the front cross beam 11.
  • a mechanism (not shown in Figure 1) for transporting the die 5 through the container 3.
  • a knife 32 for separating discards can be mounted on the frame 10, as can be also mounted a feed mechanism 7 for the billets with a clamping device 33.
  • conduits of the low-pressure main 37 are also approaching the press.
  • the heated billet 1 is fed onto the feed mechanism 7 and attached by a clamp 33 in such a way that approximately one third of the billet 1 projects from it on the side facing the container 3. Furthermore, the feed mechanism 7 is used to raise the billet 1 onto the axis of the press.
  • the reverse stroke cylinders 26,28 of the container 3 are then engaged, and the container is pushed onto the free part of the billet 1 located on the feed mechanism 7.
  • the reverse stroke cylinders are disengaged at the instant when a spacing of approximately 30-50 mm remains between the feed mechanism 7 of the billets 1 and the end face of the container 3.
  • the feed mechanism 7 is then removed and a further stroke of the container 3 (to the left in the figure) pushes the billet 1 into the cavity 2 of the container 3.
  • the hollow ram 6 emerges entirely from the container 3, and a special mechanism (not shown in the figure) is used to mount a die 5 on it.
  • Fluid is fed from the conduit of the high-pressure main 34 into the main power cylinder and the crosspiece 5 executes a short idle stroke H b I , the projections 24 on the crosspiece 8 coming into contact with the lugs 25 on the container 3, and all the said moving elements beginning to move at the same speed to the right.
  • the inner spaces of the reverse stroke cylinders of the container 3 and the inner spaces of the return cylinders of the crosspiece 8 are connected to conduits of the low-pressure main 37: there is a discharge of fluid.
  • the speed V R of movement of the ram 4 is determined at this time as the difference between the speed V b of movement of the crosspiece 8 and the speed V a of movement of the plunger 22 of the auxiliary cylinders.
  • V R V b - V a
  • the speed V C of movement of the container 3 is identical to the speed V a of movement of the crosspiece 8.
  • the speed Vb of movement of the crosspiece 8 and the speed V a of depression of the plunger 22 of the auxiliary cylinder are correspondingly directed in opposite directions. Consequently, the magnitude of the kinematic coefficient K w , is equal to the quotient of the division of the speed V b of the crosspiece 8 by the difference of the speeds of movement of the crosspiece V b and the plunger V a of the auxiliary cylinders.
  • the magnitude K w of the ratio V C /V R of the speeds of movement of the container V C and ram V R is determined by the ratio of the dimensions of the inner space 20 of the auxiliary cylinder and the inner spaces 19 of the stabilizing cylinders.
  • the cavities of the return cylinders are connected to the high-pressure main 34 (not shown in the figure) and under their action the crosspiece 8 is returned to the initial (left-hand) position.
  • fluid is ejected from the inner space 19 of the stabilizing cylinder into the inner space 20 of the auxiliary cylinder, and the auxiliary cylinder 22 is pushed out into the initial position (extreme right).
  • the reverse stroke cylinders of the container 4 then (or at the same time as the withdrawal of the crosspiece 5) extend the small movement of the container 3 to the right up to the restraining arm (not shown in Figure 1) of the container 3, the discard being withdrawn from the cavity 2 of the container 3.
  • the knife 32 is used to separate it.
  • the restraining arm 4 is then removed, and with the aid of the cylinders for moving the container (27, 29) the container 3 is displaced up to the stop into the front cross beam 11, the die 5 emerging from the container 3 on the side of the crosspiece 8, after which it is removed from the hollow ram 6.
  • the cycle can then be repeated.
  • the arrangement of the stabilizing cylinders (15,16) hydraulically connected to the inner space 20 of the auxiliary cylinders renders it possible without any control from outside automatically to obtain an optimum constant magnitude K w of the ratio V C /V R of the speeds of movement of the container V C and ram V R , that is to say to implement the process in full, in the case above, for hot extrusion with the active assistance of friction forces.
  • This extrusion press permits the required optimum ratio V C /V R of the speeds of movement of the container V C and ram V R to be kept automatically even in the case of constant change in the speed of movement of the main cylinder and, correspondingly, crosspiece 8.
  • the design of the stabilizing cylinders is very simple and they can be mounted on any press without particular difficulty.
  • the hydraulic extrusion press can have an additional hydraulic connection in the form of a conduit 38 ( Figure 2) implemented by means of connecting the inner space 19 of the stabilizing cylinder to the low-pressure main 37. It is possible to mount on the auxiliary conduit 38 a governor 39 in which, for example, it is possible to mount a controlled valve 40 and uncontrolled spring-loaded valve 41.
  • the auxiliary conduit 38 permits idle strokes of any size to be executed by the crosspiece 8.
  • An auxiliary hydraulic connection constructed in the form of a conduit 38 permits fluid to be fed from the low-pressure main 37 into the inner space 19, which is being liberated, of the stabilizing cylinders at the time of the idle stroke of the crosspiece 8, which prevents air from reaching the hydraulic system.
  • the automatic provision of the required magnitude K w of the ratio V C /V R of the speeds of movement of the container V C and ram V R , as well as reliable operation of the units of the press in process of extrusion require various design elements of the press to he constructed to accord strictly with one another.
  • the length of the cylinder body 15 and plungers 16 is selected to be equal to the length of the body 13 of the main power cylinder and its plunger 14. The selection of such relationships permits the working stroke of the crosspiece 8 to be unlimited.
  • the area of the cross-section of the auxiliary plunger 22 is equal to the total area of the cross-sections of all power cylinders which implement the working stroke of the crosspiece 8.
  • the stroke of the crosspiece 8, the plungers 14 of the power cylinders and the plungers 16 of the stabilizing cylinders consists of an idle stroke H b I and a working stroke H b w .
  • H b I idle stroke
  • H b w working stroke
  • each booster power cylinder is constructed in the form of a cylindrical body 42 in which there is arranged a plunger 43.
  • One of the said elements of each booster power cylinder can be attached in a stationary fashion to one of the cross beams (to the rear cross beam 3 in the figure), while the other can be attached in a stationary fashion to the crosspiece 8, and the inner space 44 of each of them communicates with the high-pressure main 34 and the low-pressure main 37.
  • the fluid is fed from the high-pressure main 34 only into the inner space 44 of the booster cylinders. At this time, only the fluid from the low-pressure main 36 enters the main cylinder. A large quantity of expensive fluid in the high-pressure main 34 is thereby saved.
  • fluid In order to execute the working stroke of the crosspiece 8, fluid ceases to be fed into the main cylinder from the low-pressure main 37, and fluid starts to be fed from the high-pressure main 34. It is possible to continue feeding fluid from the high-pressure main 34 into the booster cylinders. If the effort of only the main cylinder is sufficient for extrusion, fluid is fed into the booster cylinders from the low-pressure main 37.
  • the inner space 44 of each of the booster cylinders can be hydraulically connected by means of a channel 45 in the plunger 43 and a conduit 46 to the inner space 20 of the auxiliary cylinder.
  • Such a hydraulic connection permits the use of booster cylinders in addition to stabilizing cylinders.
  • ⁇ F s of the cross-sections of the stabilizing cylinders account is also taken of the area of the cross-section of all booster cylinders.
  • Valves 47, 48 can be mounted in the hydraulic extrusion press between the inner spaces 19, 44 of each hydraulic cylinder connected hydraulically 18, 46 to the auxiliary cylinder, and the high-pressure main 34 and low-pressure main 37.
  • valves 47 and 48 are open. At the instant when the idle stroke starts, fluid enters the booster cylinders through the valve 48 from the high-pressure main 34, while fluid enters the stabilizing cylinders through the valve 47 from the low-pressure main 37. After the cessation of pressing-out and the start of the metal flow of the billet 1, the valves 47 and 48 can be closed, after which fluid starts to overflow in them from the inner space 20 of the auxiliary cylinder.
  • the hydraulic connection 18, 46 between the inner space 20 and each of the inner spaces 19, 44, hydraulically connected between themselves, can include valves 49 and 50, respectively.
  • valves 49 and 50 are closed before the press starts working. During the idle stroke of the crosspiece 8 and the following stage of pressing-out of the billet 1 in the container 3, the valves 49 and 50 remain closed. After cessation of the pressing-out and the start of discharge of the metal into the channel of the die 5, the valves 47 and 48 are closed and, at the same time, the valves 49 and 50 are opened. In this case, owing to the actuating effect of the plunger 22 of the auxiliary cylinder, the fluid 43 in the inner space 20 of the auxiliary cylinder starts to overflow both into the inner space 19 of the stabilizing cylinders and the inner space 44 of the booster cylinders.
  • the valve 48 can be constructed to have three positions on the hydraulic extrusion press: the first position is closed, the second position is open to the high-pressure main 34, and the third position is open to the low-pressure main 37.
  • the valve 48 In order to feed fluid from the high-pressure main 34 into the booster cylinders, the valve 48 is set to the second position and the valve 51 is opened. In order to feed fluid from the low- pressure main 37, the valve 48 is set to the third position, and the valve 51 is closed.
  • the hydraulic extrusion press can contain a restricting unit ( Figure 3) consisting of a body 52 having two holes, an inlet hole 53 and an outlet hole 54, in which a slide valve 55 having a through space 56 is mounted.
  • the slide valve 55 interacts at one end with the spring 57, while at the other end of the slide valve 55 there is the body 58 of the hydraulic cylinder which is rigidly connected to the body 52.
  • the plunger 59 of this cylinder is rigidly attached by one end to the slide valve 55.
  • the configuration and geometrical dimensions of the through cavity 67 determine the magnitude of the ratio V C /V R of the speeds of mutual movement of the container V c and ram V R .
  • the cavity 56 is hydraulically connected via the inlet hole 53 in the body 52 to the inner space 20 of the auxiliary cylinder.
  • the through cavity 56 in the slide valve 55 is connected through the outlet hole 54 in the body 51 to the low-pressure main 37 with the aid of the conduit 61.
  • the inner cavity 62 of the body 58 of the cylinder is also connected, with the aid of the conduit 63, to the inner space 20 of the auxiliary cylinder.
  • a cover 64 is mounted on the body 52 of the restricting unit on the side of the spring 57.
  • the hydraulic extrusion press with the conduit 60 between the through cavity 56 of the slide valve 55 and the inner space 20 of the auxiliary cylinder can include a valve 65.
  • Such a press operates in the following way.
  • a stage of pressing-out of the billet 1 begins, which requires maximum energy expenditure.
  • valves 47, 48, 51 close, while the valves 49, 50 and 65 all open together or each separately.
  • the fluid from the inner space 20 of the auxiliary cylinder starts to enter the stabilizing cylinders and booster cylinders and, through the valve 65, approaches the through hole 56 in the slide valve 55 and the cavity 62 of the cylinder 58 of the restricting unit.
  • the fluid then passes through the hole 56 in the slide valve 55 and enters the low-pressure main 37 through the outlet hole 53 via the conduit 61.
  • the fluid additionally drains from the inner space 20 of the auxiliary cylinder into the low-pressure main 37 through the conduit 61, the plunger 22 of the auxiliary cylinders 21, 22 depresses more quickly and, accordingly, the ratio V C /V R of the speeds of movement of the container V c and ram V R increases.
  • the fluid from the auxiliary cylinder acts simultaneously on the plunger 58 of the restricting unit, while the latter in its turn acts on the slide valve 55, tending to move it (to the right in Figure 3). It is restrained from this movement by the spring 57 which is supported at one end in the slide valve 55 and at the other in the cover 64. Consequently, the slide valve 55 moves with each instant in time until the pressure of the fluid on the plunger 59 is compensated by the compression of the spring 57. Furthermore, the lateral surface of the billet 1 is reduced as the extrusion process proceeds, and therefore the fraction of the effort transmitted onto the billet 1 through the container 3 is also reduced, while the fraction of the effort transmitted through the ram 4 increases.
  • the pressure in the inner space 20 of the auxiliary cylinder increases continuously, with the result that the effect on the plunger 59 increases continuously.
  • the plunger 59 and slide valve 55 move continuously (to the right), compressing the spring 57 all the more strongly.
  • the configuration of the through hole 56 can be of a variable cross-section along the length of the slide valve 55. During the extrusion process different through cross-sections for the fluid are obtained in the auxiliary restricting unit.
  • the ratio V C /V R of the speeds of movement of the container 3 and ram 4 is variable in the course of the cycle of extrusion.
  • the law of variation in the ratio V C /V R of the speeds is determined by the configuration and geometrical dimensions of the through channel 56 in the slide valve 55.
  • the law of variation in the ratio V C /V R of the speeds of movement of the container V c and ram V R is selected in the optimum interval indicated above, and it depends on the extruded material and the technical parameters of the process.
  • valve 65 In the case when it is necessary to pass to a constant ratio V C /V R of the speeds of movement of the container V c and ram V R , the valve 65 is close in the course of the process.
  • the cover 64 ( Figure 3) on the body 52 of the auxiliary restricting unit can be mounted with the possibility of axial movement in order to control the magnitude of the precompression of the spring 57.
  • the magnitude of the precompression of the spring 57 it is possible to change the law of motion of the slide valve 55 in the process of extrusion and, consequently, the law of variation in the ratio V C /V R of the speeds of movement of the container V c and ram V R .
  • a lead screw 66 attached in a stationary fashion to the end face of the slide valve 55 on the side of the spring 57.
  • the cover 64 has a through hole 67 for the passage of the lead screw 66.
  • the hole 67 in the cover 64 and the lead screw 66 are mated, for example, in a threaded fashion.
  • the cylindrical body 21 and, correspondingly, the plunger 22 of the auxiliary cylinder can be constructed in a stepped fashion. Formed as a result of such a design are steps of the plunger 22 which are of larger diameter 68 and lesser diameter 69 and two inner cavities, an annular one 70 and a cylindrical one 71.
  • the inner cavities 70 and 71 inter-communicate hydraulically with the aid of a conduit 72.
  • the auxiliary cylinder with the stepped plunger 22 operates in a manner analogous to the auxiliary cylinder with the cylindrical plunger 22 of the press ( Figure 2) whose operation has been described above.
  • auxiliary cylinder 21, 22 in a stepped fashion renders it possible to preserve the required area of the cross-section of the auxiliary cylinder, to have large guides for the plunger 22 and to reduce the dimensions of the crosspiece 8. This is explained by the fact that as a result of the hydraulic connection by means of the conduit 72 the area of the cross-section of the plunger 22 is determined by the dimension of its largest step 68.
  • a step 69 of small diameter of the body 21 of the auxiliary cylinder and the plunger 22 Serving as the fundamental guide of the plunger 22 is a step 69 of small diameter of the body 21 of the auxiliary cylinder and the plunger 22.
  • This step 69 of the plunger 22 is constructed with a significant length (a few diameters of the step itself), while the step 68 of larger diameter of the auxiliary cylinder is constructed with a short length.
  • Such an implementation of the larger step 68 of the plunger 22 of the auxiliary cylinder permits a significant reduction in the dimensions of the crosspiece 5 and, consequently, in the dimensions of the entire press
  • the lesser step 69 of the auxiliary cylinder can be arranged partly in the main plunger 14 of the press, as is shown in the same Figure 4.
  • the hydraulic extrusion press being patented permits a thorough realization of the process for extrusion with the active assistance of friction forces.
  • the design of the hydraulic extrusion press being patented is simple and reliable in use and permits the required ratio of the speeds of movement of the container and ram to be maintained automatically throughout the entire operating cycle. It is possible, on the press being patented, simply by switching the valves, to obtain one or other ratio of the speeds of movement of the container and ram required for the manufacture of a concrete product.
  • the hydraulic extrusion press Owing to the implementation of a stepped plunger of the auxiliary cylinder and to partial arrangement of that plunger in the body of the plunger of the main cylinder, the hydraulic extrusion press being patented has small overall dimensions.
EP94906412A 1993-11-10 1993-12-15 Process for the hot extrusion of metal with the active assistance of friction forces, and a hydraulic extrusion press for carrying out this process Withdrawn EP0747144A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
RU93050907 1993-11-10
RU93050907A RU2105621C1 (ru) 1993-11-10 1993-11-10 Способ горячего экструдирования металла с активным действием сил трения и гидравлический экструзионный пресс для его осуществления
PCT/RU1993/000303 WO1995013150A1 (fr) 1993-11-10 1993-12-15 Procede d'extrusion de metal a chaud avec l'aide active de forces de friction, et presse d'extrusion hydraulique prevue a cet effet

Publications (2)

Publication Number Publication Date
EP0747144A4 EP0747144A4 (en) 1996-12-04
EP0747144A1 true EP0747144A1 (en) 1996-12-11

Family

ID=20148987

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94906412A Withdrawn EP0747144A1 (en) 1993-11-10 1993-12-15 Process for the hot extrusion of metal with the active assistance of friction forces, and a hydraulic extrusion press for carrying out this process

Country Status (3)

Country Link
EP (1) EP0747144A1 (ru)
RU (1) RU2105621C1 (ru)
WO (1) WO1995013150A1 (ru)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2319199A (en) * 1996-09-19 1998-05-20 Sanyo Special Steel Co Ltd Die forging system
WO2005035157A1 (de) * 2003-10-07 2005-04-21 Alcan Technology & Management Ltd. Temperaturreguliertes materialumformverfahren und vorrichtung zur durchführung des verfahrens
CN101985150A (zh) * 2010-08-02 2011-03-16 天津市天锻压力机有限公司 具有等温锻造和压制电极复合功能的液压机

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2478136C2 (ru) * 2011-07-15 2013-03-27 Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Уфимский государственный авиационный технический университет" Ультрамелкозернистые алюминиевые сплавы для электротехнических изделий и способы их получения (варианты)
WO2016070027A1 (en) 2014-10-31 2016-05-06 Massachusetts Institute Of Technology Compositions and methods for arranging colloid phases

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3670542A (en) * 1969-12-04 1972-06-20 Reynolds Metals Co Extrusion method and apparatus
US4230661A (en) * 1977-10-15 1980-10-28 Kobe Steel, Limited Indirect extrusion process

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2196860B1 (ru) * 1972-08-24 1977-08-05 Morane Somua Pr Sses Mat
SU623604A1 (ru) * 1976-11-22 1978-09-15 Предприятие П/Я Г-4361 Способ получени изделий
SU645721A1 (ru) * 1977-01-04 1979-02-05 Московский институт стали и сплавов Способ прессовани изделий
SU676347A1 (ru) * 1977-05-24 1979-07-30 Предприятие П/Я В-8173 Способ прессовани труб
DE3023388A1 (de) * 1980-06-23 1982-01-21 Schloemann-Siemag AG, 4000 Düsseldorf Indirekt-metallstrangpresse und arbeitsverfahren zum entfernen von eingefrorenen bloecken aus einer solchen presse

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3670542A (en) * 1969-12-04 1972-06-20 Reynolds Metals Co Extrusion method and apparatus
US4230661A (en) * 1977-10-15 1980-10-28 Kobe Steel, Limited Indirect extrusion process

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Section Ch, Week 7927 Derwent Publications Ltd., London, GB; Class M21, AN 79-50514B XP002019554 & SU-A-623 604 (BELOZEROV A P) , 2 August 1978 *
DATABASE WPI Section Ch, Week 7943 Derwent Publications Ltd., London, GB; Class M21, AN 79-78759B XP002019553 & SU-A-645 721 (MOSCOW STEEL ALLOYS INST) , 8 February 1979 *
DATABASE WPI Section Ch, Week 8013 Derwent Publications Ltd., London, GB; Class M21, AN 80-23389C XP002019555 & SU-A-676 347 (OSTRENKO V YA) , 30 July 1979 *
See also references of WO9513150A1 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2319199A (en) * 1996-09-19 1998-05-20 Sanyo Special Steel Co Ltd Die forging system
US5894752A (en) * 1996-09-19 1999-04-20 Sanyo Special Steel Co., Ltd. Method and system for warm or hot high-velocity die forging
GB2319199B (en) * 1996-09-19 1999-05-26 Sanyo Special Steel Co Ltd Method and system for warm or hot high-velocity die forging
WO2005035157A1 (de) * 2003-10-07 2005-04-21 Alcan Technology & Management Ltd. Temperaturreguliertes materialumformverfahren und vorrichtung zur durchführung des verfahrens
CN101985150A (zh) * 2010-08-02 2011-03-16 天津市天锻压力机有限公司 具有等温锻造和压制电极复合功能的液压机
CN101985150B (zh) * 2010-08-02 2013-06-12 天津市天锻压力机有限公司 具有等温锻造和压制电极复合功能的液压机

Also Published As

Publication number Publication date
RU2105621C1 (ru) 1998-02-27
WO1995013150A1 (fr) 1995-05-18
EP0747144A4 (en) 1996-12-04

Similar Documents

Publication Publication Date Title
JP4357458B2 (ja) 溶融金属を加圧して連続的に供給するシステム及び連続金属成形品の製造方法
US20090113977A1 (en) Method and apparatus for forming of panels and similar parts
US6360576B1 (en) Process for extruding a metal section
KR20020075183A (ko) 난가공재의 결정립 미세화장치 및 방법
EP0739662A1 (en) Friction-assisted hot extrusion method for producing hollow articles and a hydraulic press for carrying out said method
EP0747144A1 (en) Process for the hot extrusion of metal with the active assistance of friction forces, and a hydraulic extrusion press for carrying out this process
KR100400706B1 (ko) 작업물을 열간 프레스하는 방법
US5836190A (en) Process for extruding a section or the like from an ingot and a device that purpose
RU2166394C1 (ru) Способ изготовления стальных бесшовных труб
US5740688A (en) Pressure-assisted formation of shaped articles
RU2116155C1 (ru) Способ пластического структурообразования высокопрочных материалов
US2905317A (en) Metal tube press
US2142703A (en) Method of and apparatus for extruding elongated solid and hollow metal shapes
RU2168382C1 (ru) Способ изготовления легкосплавных труб
US5893287A (en) Method and device for combined drawing and hydrostatic extrusion of billets from metal and alloys
US20030222121A1 (en) Die casting sprue system
SU504574A1 (ru) Способ прессовани труб
EP2566655B1 (en) Piston assembly multiple step forming process
RU2440864C1 (ru) Способ полунепрерывного гидромеханического прессования заготовок
JP4054153B2 (ja) 孔を有する鍛造部品の製造方法および製造装置
US2755544A (en) Metal treatment
RU2033886C1 (ru) Способ производства металлопродукции и устройство для его осуществления
Denisov Investigation of the pressure and heat treatment effect on the ICE piston blanks mechanical and structural properties from high-strength aluminum alloy B95
RU2285570C1 (ru) Устройство для прессования с активным действием сил трения
RU2084304C1 (ru) Способ гидропрессования точных профилей из сплавов цветных и благородных металлов

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

A4 Supplementary search report drawn up and despatched
AK Designated contracting states

Kind code of ref document: A4

Designated state(s): AT CH DE ES FR GB IT LI SE

17P Request for examination filed

Effective date: 19960528

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT CH DE ES FR GB IT LI SE

17Q First examination report despatched

Effective date: 20000125

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20000805