US2671557A - Extrusion press - Google Patents

Description

2 Sheen-Shoot 1 Filed June 5, 1952 INVENTOR. Azm mvo M Fi BY HTTOK/VEKS' March 9 1954 R. M. REICHL 57 EXTRUSION PRESS Filed June, 5, 1952 2 Sheets-Sheet 2 Fi g5 INVENTOR. Fry M0410 JPJ/C/ZL Patented Mar. 9, 1954 EXTRUSION PRESS Reymond M. Reichl, Forest Hills, N. Y., assignor to Hydropress, Incorporated, New York, N. Y., a corporation of Delaware Application J nine 5, 1952, Serial No. 291,937

5 Claims. 1

This invention relates to improvements in apparatus for plastically forming material as by extrusion, and more particularly relates to improvements in metal extrusion presses.

Metal extrusion presses of the type with which the present invention is illustrated herein employ a relatively stationary platen, a movable billet container, and an extrusion tool operating ram means, the container being mounted between the platen and the ram, the platen having means for supporting a die between it and the billet container, and the billet container, during the working stroke of the extrusion plunger, having face-to-face sealing contact with said die. The billet container is usually supported on machined guideways which are located below the center line of the press. Usually there are dif-- ferences in friction between such supporting guideways and the sliding container housing, and there also may be a difference in the action of the multiple container shifting means, usually hydraulic cylinders, connected thereto at points spaced on both sides of the vertical center of the press. The latter difference may arise from differences of internal friction in such two shifting cylinders. As a result of the difference in the forces acting on the opposite sides of the billet container, such container sometimes has a tendency to turn angularly with respect to the guideway, that is to cock, while it carries out its working stroke in traveling toward the platen so as to bear against the die. This cooking of the container is accentuated if a further misalignment occurs, as when residue of the extruded substance sticks to the face of either the die or the billet container at the zone wherein the container and die normally efiect sealing contact with each other. Under such conditions, and while the means, such as hydraulic cylinders, for moving the billet container are developing their maximum sealing pressure, thecocking of the container becomes acute. When this occurs, very large forces are transmitted from such billet container moving and sealing means, such forces tending to throw the billet container out of alignment on the guideways of the press bed. Such action has resulted in severe wear of the guiding means and guide surfaces on the press bed and container, respectively. and even in breakage of the container housing or of the bed plate of the press on which the guideways are mounted.

The present invention provides novel apparatus for moving the billet container of extrusion presses and for holding the container against the die, the apparatus being of such design and construction that the tendency of the billet container to cock on the guideway of the press will be controlled. Further, the movement of the billet container toward the platen is carried out by a yielding power means at a low power range, the power being large enough merely to overcome friction and to assure positive movement of the container and its housing on the press guideway. During such initial driving movement of the billet container by such yielding driving means, any tendency of the container to cook, should it exist, will have no untoward results, since the power exerted on the billet container is so small that it cannot cause damage to the parts. The apparatus of the invention further includes means for detecting the required initial, substantially full-faced, contact between the billet container and the die, and, when such contact is established, for initiating the application of high power further to thrust the billet container against the die under high pressure to effect sealing contact between the container and the die. Should the aforementioned initial, substantially fullfaced, contact between the die and the billet container not be established, the apparatus is of such construction that high power for thrusting the billet container toward closing position will not be applied. Thus, the previously experienced severe cocking of the billet container and large lateral pressures thereon, which result in the described undue wear and even breakage of the parts, is avoided by use of the apparatus of the invention.

In one aspect, a single source of power can be used in conjunction with a relief valve and a solenoid controlled valve for rendering the relief valve ineflective when substantially full-faced contact has been established. In another aspect, asource of low power and a source of high power can be used.

The invention will be more readily understood by consideration of the accompanying drawings, forming a portion of the present specification, which are merely exemplary.

In the drawings:

Fig. 1 is a view partially in side elevation and partially in longitudinal vertical section of a metal extrusion press embodying the apparatus of the invention, the section being taken along the line l-l of Fig. 2;

Fig. 2 is a view in transverse vertical section through the apparatus of Fig. l, the section being taken along the line 2-4 in Fig. 1;

Fig. 3 is a further view in transverse vertical section through the apparatus of Fig. 1, the section being taken along the line 3-3 in Fig. 1;

Fig. 4 is a schematic view of a portion of the extrusion press including the billet container moving cylinders and the controller for such cylinders, such controller including the operating valves for such cylinders, the electric control circuits for such valves, and the switches therefor;

Fig. 5 is a schematic view of a portion of the extrusion press including the billet container, the die, and the platen, showing the relationship which exists between the parts when a bit of foreign matter, such as a piece of the billet last extruded, lodges between the billet container and the die;

Fig. 6 is a view similar to Fig. 5 with the exception that, whereas in Fig. 5 the confronting faces of the platen and billet container are parallel, in Fig. 6 the foreign matter between the die and the billet container has caused the billet container to be cocked out of parallelism with the platen; and

Fig. 7 is a schematic view of a portion of the extrusion press similar to Fig. 4 except that an arrangement is shown having a single source of power.

The extrusion press with which the invention is illustrated is of a conventional type for extruding metal wherein the bed of the press extends horizontally and the motion of the tools and of the billet container is in a horizontal direction. It is to be understood, however, that the invention may be applied to various other types of apparatus for plastically forming material, and that it may be applied to other types of metal extrusion presses such as those of the vertical type.

The extrusion press shown has a bed 2 on the right-hand end of which is mounted a cross head 3 which supports the main power cylinder ill for the tool moving. At the left-hand end of the bed 2 of the press, there is mounted the platen and die supporting structure 6. The two end structures 4 and 8 of the press are connected together, as shown, by three parallel longitudinally xtending tie rods, two tie rods 24 being at the bottom adjacent the bed of the press and one tie rod 22 being at the top thereof.

The main power cylinder I3 is provided with the customary fluid inlet and outlet l2. The piston rod or ram H of cylinder ID has connected thereto at its outer end the movable cross head It on which is mounted the extrusion stem or tool means III. The power thrust of ram I4 is to the left, head l3 being returned to the right by the pull back motors 23 which have their piston rods or rams 2| connected to the cross head It, as shown.

The platen 23 of the fixed structure 6 of the extrusion press has a central opening 23 therethrough for the reception of the material extruded. The die arrangement is generally designated 30. The die 32 is held in operative position so that it is coaxial with the extrusion plunger I3, the bore through the billet container, and the opening 23 through the platen. The billet container housing 34 supports the main body portion 36 of the container, such portion 38 having centrally thereof the renewable liner member 38 within the bore of which the billet to be extruded is placed. The container housing 34, which is generally triangular in vertical section as shown in Fig. 3, has a guide shoe at each of its apices, the guide shoes at each of the apices at the bottom of the container housing being desig- 4 nated 40, such shoes riding upon guideways provided at the top of the bottom tie rods 24. At the top of the container housing there is provided a third guide shoe 4|, guide shoe 4| engaging with guide surfaces provided on the top tie rod 22.

The container housing 34 is moved toward and away from the platen 26 by the two hydraulic cylinders 42 which are supported in the platen with their axes parallel to the axis of the container housing. Each of such cylinders 42 has a piston 58 slidably mounted therein, the piston having a rod 44 projecting from the right-hand end of the cylinder. The outer ends of such piston rods are threaded, as shown, and project through bores in the billet container housing, being secured thereto by nuts on both sides of the piston rod. Preferably, the cylinders 42 are located as shown with their axes positioned on the line H (Fig. 2) which passes through the axis of the element 33 of the billet container. As a result of such mounting, maximum accessibility of the tools is obtained while maintaining a very satisfactory distribution of the thrust imposed upon the billet container housing by cylinders 42.

The structure of the extrusion press so far described above is conventional. It will be understood by those skilled in the art.that at the initiation of a typical working cycle of the apparatus, the movable cross head It supporting the extrusion tool means l3 will have been retracted to the right, as shown in Fig. 1, and the billet container housing 34 will have been thrust to the right by cylinders 42, thereby markedly separat ing the left-hand end of the billet container from the die 32. The cylinders 42 are then operated, after the die has been placed in the correct position on the platen, to thrust the billet container to the left and into contact with the right-hand end of the die, whereby such die is forcibly clamped between the platen and the billet container so as to effect a seal between such parts. The metallic billet, heated in the case of the extrusion of the hard metals, or unheated when the apparatus is employed for extruding the softer metals such as lead, is then charged into the opening in the billet container lining member 33. The cylinder III is operated to move the extrusion tool means to the left and into the opening in the billet container, whereby to extrude the metal of the billet to the left.

The apparatus of the invention includes means for controlling the pressure of the fluid admitted to the right-hand ends of cylinders 42, thus causing the billet container 34 to travel to the left. Should there be any foreign material, such as parts of billets previously extruded, at the interface between the die and the billet container, as shown in Figs. 5 and 6, so that full-faced contact between such parts and substantial parallelism between their confronting faces cannot be attained, the cylinders 42, and thus the billet container 34, will be subjected only to low pressure fluid initially introduced thereto to eifect the initial travel of the billet container to the left. Should, however, the billet container be able to advance into substantial full-faced contact with the die and with the confronting faces of such elements lying substantially parallel to each other, the right-hand spaces in cylinders 42 are then subjected to fluid of much higher pressure whereby sealing between the billet container and the die is effected.

The structure of the above mechanism for governing the travel of the billet container 34 to the left, in accordance with the invention, will be understood by a consideration of Figs. 4, and 6 wherein a source of low pressure and a source of high pressure fluid i employed. In Fig. 4, the apparatus is diagrammatically shown in the position the parts assume when the billet container has effected full-faced contact with the right-hand end of the die. In Figs. 5 and 6 the apparatus is shown in the condition the parts assume when intervening foreign material prevents the attainment of such full-faced contact between the billet container and the die, such latter two figures showing, in addition, how the apparatus of the invention under such conditions prevents the subjection of the billet container to the high pressure sealing force.

As shown, the two cylinders 42 are connected in parallel, the left-hand ends of such cylinders being connected by pipe 92 and branch pipe 94, the pipe 82 leading into a controlling device generally designated 61, by means of which it is selectively connected to a source of low pressure fluid, or to an exhaust sump. The right-hand ends of the cylinders 42 are connected together through the medium of the pipe 88 and branch pipe 98, the pipe 88 likewise leading into the controller generally designated 61 by means of which it is selectively connected to the aforementioned source of low fluid pressure, a source of high fluid pressure, or to said exhaust sump. In the embodiment shown, the reversal of the direction of travel of the pistons in cylinders 42 is under the manual control of the operator of the press by an electric switch, as is the operation of the main power cylinder I0 by conventional control means, not shown. The subjection of pipe 96 leading to the right-hand spaces in cylinders 42, selectively to low or high pressure fluid when the pistons 56 have been caused initially to travel to the left is under the control of automatic means for detecting substantially a full-faced contact between the billet container and the die.

In the embodiment shown, such means takes the form of the opposed pairs of electrical contacts, 48 and 52 as one set, and 50 and 54 as the other set, one contact of each set being mounted on a fixed part of the press structure such as the platen in the embodiment shown, and the other contact of each set being mounted on the container housing. The sets of contacts are connected in series in the manner to be described in the control circuit for the pressure selecting valve of the controller 81, so that such valve will admit high pressure fluid to cylinders 42 only when the controlling circuit is completed through both sets of contacts. Preferably the sets of contacts are located symmetrically on opposite sides of the center of the die on a substantially diametral line thereof, as shown in Figs. 2 and 3. As a result, when properly adjusted, such contacts will effect a closed operating circuit only when the billet container and the die have attained a substantially full-faced contact and have their confronting faces in substantial parallelism.

The two valves, generally designated 80 and 62. of the controlling means 61 are commercial- 1y available solenoid operated valves and are thus illustrated, for purposes of simplicity, only diagrammatically. Valve 80 has a main, fluid controlling, body portion 18, and at either end thereof an operating solenoid I00 and I02. Pipe 64. connected to a suitable source of low pressure fluid (not shown), has the check valve 84 connected therein so that such fluid may enter valve body I8 through the port 82 but cannot escape through such port into line 84. The source of high pressure fluid (not shown) is connected to the pipe 86 which in turn is connected to the inlet port I0 of the valve 62. Such valve has a main fluid conducting body portion 68 and an operating solenoid I4, therefor. A further port I2, opposite port I0 of valve body 68, is connected by means of pipe I8 with the port 80 at the bottom right-hand end of the valve body 18 of valve 60. The above described pipe 86 leading to the right-hand ends of cylinders 42 connects with pipe 16, as shown. The valve body 18 is further provided at the bottom left-hand end thereof with a further port 90 to which is connected the above described pipe 92, and centrally thereof with an exhaust port 88 which is connected to the exhaust pipe 88 leading to a suitable sump (not shown).

The valve 60, which as above mentioned, is of conventional commercially available design, is so constructed and arranged that when both solenoids I00 and I02 are de-energized, all of the ports 80, 82, 86, and 90 are blocked. When solenoid I00 is energized and solenoid I02 is de-energized, the movable valve element of such valve is shifted so as to connect ports 80 and 82, and further to connect ports 86 and 90. Further, when solenoid I00 is de-energized and solenoid I02 is energized, the movable valve element of valve shifts so as to connect ports 82 and 90 and also so as to connect ports and 86.

The solenoids I00 and I02 are under the control of the manually operated switch II 0, the switch being of such construction that when the movable plunger thereof is in the depressed position shown, solenoid I 00 is energized, the circuit proceeding from the source L2 to the contact 6', through the switch element I I8, to the contact H6, and through the wire I30 to the solenoid I00. The other side of th solenoid receives current constantly from the source L1 through the wire I06. In such depressed condition of the switch plunger, the circuit between supply wire I32 for solenoid I02 and the source L2 is broken. Should, however, the switch plunger be raised, contact between elements 6', II8, and II 6 is broken but, on the other hand, it is efiected through the contacts I20, th bridge element I22,

and the contact I20, thereby energizing the solenoid I02 which has the other side thereof constantly connected to line L1 through the wire I08. It will be evident from the above that when the movable element of the switch I 00 is depressed as shown in Fig. 4, the billet container 34 will travel to the left, the right-hand spaces in cylinders 42 being subjected to low pressure fluid. When the movable element of switch I00 is raised, however, to energize solenoid I02, the billet container 34 moves to the right under the driving influence of such low pressure fluid source. It will also be evident from the above that, if the plunger of switch IIO should be moved to a central position so as to de-energize both solenoids I00 and I02, the travel of billet container 34 will cease.

The switch IIO includes a bottom set of contacts H2 and I I2 which are interposed in the control circuit for the solenoid I4 of valve 62. Contacts 2' and H2 are bridged by the element II4 when the switch plunger is in depressed condition as shown, whereby to connect the supply wire I24 to the line L2 of the current source. Wire I24 is connected to the tactile switch contact 54. The tactile contacts 50 and 48 are bridged,

as shown, by the jumper wi I28. The remaining tactile contact 52 is comiected by wire I28 to one side of the solenoid I4. The other side of the solenoid I4 is permanently connected to the line L1 by the wire I04. It will thus be apparent that solenoid I4 will be energized only when the plunger of switch H is in the depressed condition shown and when contact is effected both between tactile contacts 50 and 54 and also tactile contacts 48 and 52, since all of such contacts I I2, H2, 50, 54, 48, and 52 are in series in the control circuit for the solenoid 14. The valve 52 which, as above noted, is of a conventional commercially available type, is of such design that when solenoid I4 is de-energized, communication between the ports 10 and I2 is blocked. and that when solenoid 14 is energized ports 10 and 12 ar connected. The thus described control including the valve 32, the switch H0, and the contacts 50-, 54, and 48, 52 function to prevent the admission of high pressure fluid into th right-hand ends of cylinders 42 unless the switch H0 is depressed to direct fluid into such right-hand ends of the cylinders and also unless the control circuit for solenoid 14 is completed by contact effected through both sets of the tactile contacts.

Assuming that th switch IIO has been placed in the position shown whereby the solenoid I00 is energized and the solenoid I02 is de-energized, the billet container 34 will travel to the left under the influence of the low pressure hydraulic fluid admitted from pipe 64 to the right-hand ends of the cylinders 42. Solenoid 14 remains deenergizcd until its control circuit is completed by contact between contacts 50 and 54 and between contacts 48 and 52. Such contacts cannot be effected until there is a substantial full-faced contact between the billet container and the die. Such contact may be prevented by the lodging of a piece of foreign material 58, as shown in Fig. 5,

between the die and the billet container. As there shown, such elements remain in substantial parallelism but are spaced an appreciable distance from each other whereby both sets of contacts 50, 54, and 48, 52 are open. Under such conditions, of course, solenoid I4 remains de-energized and thus cylinders 42 cannot be subjected to the highpressure fluid in pipe 66. The same result is attained if foreign material 53 should lodge between the die and the container billet in the manner shown in Fig. 6, wherein'the billet container is shown tipped with respect to the die whereby contact is effected between the contacts 50 and 54. Under such conditions. which will occur usually with the present apparatus only when the press parts are substantially worn, the control circuit to solenoid I4 still remains open due to lack of contact between contacts 48 and 52. Consequently, under such condition as well, the cylinders 42 cannot be subjected to the high pressure fluid from pipe 36 and the billet container 34 will merely remain in stalled condition, pressed to the left under the influence of the low pressure fluid. Such low pressure fluid, however, is not of sufiicient strength to damage the parts when they are stalled in either of the positions shown in Figs. or 6.

It is usually desired that the operator shall be warned of conditions such as shown in Figs. 5 and 6, wherein a seal has not been effected between the die and th billet container. This may most conveniently be done by the provision of an indicator light I50 which is connected across the leads to the solenoid 14. The indicator light thus connected will not be lighted until the solenoid I4 8 is operated; when it is lighted it will indicate substantially full-faced contact between the die and the billet container and also the fact that the billet container is being subjected to high pressure fluid to seal such elements together.

An alternative form is illustrated in Fig. 7 wherein identical parts have been given the same reference numerals as in Figs. 4, 5, and 6. In this alternative form, a single source of pressure is used, this source advancing the container at low pressure until resistance is encountered. A relief valve can be provided to limit the pressure in the cylinders 42 unless full faced contact is detected, control means being provided to render the relief or pressure limiting valve ineffective.

Pressure source I can be connected to control valve I3I, the control valve being conventional and having an exhaust connection at I31. Pipe I32 is connected with the right hand ends (Fig. 7) of cylinders 42, the left hand ends being connected by pipes I33 with the control valve I3I so as to be selectively connectable with the source of pressure or exhaust sump as described in the previous form. A relief valve I34 can be connected to line I32, said relief valve being set to open at a predetermined pressure. The connection to relief or pressure limiting valve I34 can be controlled by solenoid operated valve I35, valve I35 being normally open. Solenoid I30 can be connected in series with a source of control power I33, electrical contacts 48, 52 as one set, and and 54 as the other set. Thus, when full faced contact is made and both sets of switches are closed, valve I35 will close to render relief valve I34 ineffective and permit high or full pressure to be developed in cylinders 42.

Various modifications can be made in the control circuit of this last mentioned form. For example, the relief valve couid be arranged to be directly rendered ineffective by the solenoid.

Whereas for purposes of illustration I have shown and described a preferred embodiment of the metal forming apparatus, specifically a metal extrusion press, of the invention, it will be understood that the invention is capable of consider able variation as to details. Thus, for example, whereas I have shown a means for detecting substantially full-faced contact between the die and the billet container as being switches in which one contact of each switch is carried on a fixed part of the apparatus and the other contact of each set of the switches is carried on the billet container of the apparatus, it will be apparent that such detecting devices may be microswitches carried entirely by one movable part of the apparatus, magnetic switches, electronic capacitors, or other similar devices. It will also be apparent that, whereas in the embodiment shown the operating solenoid for the pressure selecting valve of the controller is energized by such substantially full-faced contact detecting means, the apparatus may be so constructed and arranged that the pressure selecting valve will operate to admit high pressure fluid to the cylinders only upon de-energization of the solenoid. The invention is, therefore, not limited to the embodiment of the apparatus shown but is to be defined by the scope of the claims appended hereto.

What is claimed is:

1. In an extrusion press, the combination including a flxed means, a movable means reciprocable toward and away from said fixed means, yieldable power means connected with said movable means initially moving said fixed and movable means relatively toward each other and normally into substantial contact with each other, control means including elements detecting said substantial contact, said elements being operated by such substantial contact to render the yieldable power means operative to cause said fixed and movable means to be moved toward each other under higher pressure than when initially moved toward each other after said substantial contact has been made.

2. In an extrusion press having a platen, a billet container reciprocable relatively toward and away from said platen, a die, and means to mount the die between the billet container and the platen, yieldable low power means to initially move the billet container toward the platen normally into initial substantial contact with the die, means for detecting said substantial contact, and means responsive to said means for detecting said contact to thrust the billet container against the die under high pressure when such initial substantial contact is made.

3. In an extrustion press having a platen, extrusion tool means, means to support and reciprocate the extrusion tool means in a path toward and away from the platen, a billet container mounted between the last named means and the platen, said billet container being reciprocable along the path in which the extrusion tool means moves, a die, and means to mount the die in alignment with the extrusion tool means between the billet container and the platen, yieldable power means to traverse the billet container toward the die and platen normally into initial substantial contact with the die with the confronting elements of both such elements parallel, means for detecting said substantial contact, and means connected to said means for detecting said substantial contact for thrusting the billet container against the die under high pressure only when such initial substantial contact is made.

4. In an extrusion press having a platen, an extrusion tool means, means to support and reciprocate the extrusion tool means in a path toward and away from the platen, a billet container mounted between the last named means and the platen, said billet container being reciprocable along the path in which the extrusion tool means moves, a die, and means between the billet container and the platen, the combination for moving the billet container which comprises power means to traverse the billet container toward the die and platen and into contact with said die, said power means having selectively a first, low power, range and a second, high power, range, detecting means for determining when initial substantial contact between the billet container and die takes place, and a controller for the power traversing means, said controller operating to efifect the traverse of the billet container into said initial substantial contact with the die at the low operating range of the power means, the controller further operating to cause the power traversing means to thrust the. billet container against the die under high pressure when said detecting means determines such initial substantial contact is made.

5. In an extrusion press having a platen, an extrusion tool means, means to support and reciprocate the extrusion tool means in a path toward and away from the platen, a billet container mounted between the last named means and the platen, said billet container being reciprocable along the path in which the extrusion tool means moves, a die, and means to mount the die in alignment with the extrusion tool means between the billet container and the platen, the combination for moving the billet container which comprises power means to traverse the billet container toward the die and platen, said power means having selectively a first, low power, range and a second, high power, range, tactile means interacting between the billet container and a fixed part of the apparatus for detecting substantially fullfaced contact between the billet container and the die, means responsive to the last named means for controlling said power traversing means, and a control circuit for the controlling means, said tactile means comprising two electric switches connected in series in the control circuit for the controlling means, said switches being mounted between the platen and billet container symmetrically on opposite sides of the center of the die on a substantially diametral line thereof, the controlling means operating to effect the traverse of the billet container into initial substantial contact with the die at the low operating range of the power means, the controlling means further operating to cause the power traversing means to thrust the billet container against the die under high pressure when such initial substantial contact is made. A

REYMOND M. REICHL.

References Cited in the file of this patent UNITED STATES PATENTS Number

Images