US3696652A - Continuous material deformation process and apparatus therefor - Google Patents

Continuous material deformation process and apparatus therefor Download PDF

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US3696652A
US3696652A US862673A US3696652DA US3696652A US 3696652 A US3696652 A US 3696652A US 862673 A US862673 A US 862673A US 3696652D A US3696652D A US 3696652DA US 3696652 A US3696652 A US 3696652A
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workpiece
agency
deforming
extrusion
rod
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Francis Joseph Fuchs Jr
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AT&T Corp
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Western Electric Co Inc
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/007—Hydrostatic extrusion
    • B21C23/008—Continuous extrusion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/007—Hydrostatic extrusion

Definitions

  • ABSTRACT A process and apparatus for practicing the process wherein a workpiece of indefinite length, e.g., a metal rod, is continuously deformed by a deforming agency to produce a product of indefinite length, e.g., wire.
  • the continuity of the deformation is achieved by intermittently advancing the workpiece into the deforming agency, e.g., a controlled flow of pressurized fluid or a conventional extrusion die, intermittently advancing the deforming agency over the workpiece, and controlling the intermittent advances of the workpiece and the deforming agency to maintain a desired relative velocity between the workpiece and the deforming agency.
  • a novel workpiece clamping apparatus wherein a segmented cylinder is used as a clamping device for gripping a workpiece.
  • This invention relates to the deformation of material to form a product, and in particular, to a method and apparatus which is useful for continuously deforming a workpiece, e.g., rod, to form a product, e.g., wire.
  • This invention is particularly useful in passing an indefinite length of rod against a deforming agency to deform the rod, thereby continuously extruding the rod to form wire.
  • This type of extrusion involves positioning a billet within a billet container having an extrusion die positioned in one end, and surrounding all but the die-adjacent surface of the billet with a pressure transmitting fluid so. as to exert a high pressure thereon and extrude the billet material through the die.
  • This process reduces the amount of work necessary to accomplish extrusion in that the friction between the surface of the billet material and the surface of the billet container is eliminated by the presence of the pressurizing fluid therebetween.
  • Extrusion such as this is shown in greater detail in Canadian Pat. No. 476,793 to P. W. Bridgman which issued on Sept. 1 l, 1951.
  • a primary obstacle in the development of a continuous noninterrupted extrusion process has been the trend in extrusion processes to accomplish deformation in a generally high pressure environment. Specifically, the available methods of feeding billet material into such a high pressure environment have not been satisfactory.
  • an axial stress be built up in the rod as it is passed from an ambient environment, e.g., substantially zero or room pressure, into the high pressure environment, e.g., pressure in an amount at least equal to that pressure necessary to accomplish deformation of the material.
  • an ambient environment e.g., substantially zero or room pressure
  • the high pressure environment e.g., pressure in an amount at least equal to that pressure necessary to accomplish deformation of the material.
  • care must be taken to avoid deformation, e.g., by sinking or bulging, except as desired.
  • radial support pressure In order to prevent rod bulging, radial support pressure must be applied to the rod, commencing at the entry to the high pressure environment, which support pressure must be of sufficient magnitude to counteract the axial stress in such a manner as to insure that the axial stress in the rod does not exceed the radial stress generated by the support pressure by an amount greater than the yield strength of the rod material.
  • the radial support pressure must be controlled so as to not generate a radial stress which exceeds the axial stress by an amount greater than the rod yield strength, otherwise, sinking or pinch-off will occur.
  • the axial stress and the radial stress in the rod being fed must be controlled in such a manner as to preclude either of the stresses exceeding the other by an amount in excess of the yield stress of the rod material, except in a zone of deformation wherein deformation of the rod is accomplished as desired to form a product of indefinite length.
  • the present invention relates to a method for deforming a workpiece of indefinite length to form a product of indefinite length.
  • a method according to the invention may include the steps of intermittently advancing a workpiece into a deforming agency, intermittently advancing the deforming agency onto the workpiece, controlling the intermittent advances of the workpiece and the deforming agency to maintain a desired relative velocity between the workpiece and the deforming agency, and continuously deforming the workpiece by the deforming agency to produce the product.
  • Such a workpiece clamping device may include a plurality of longitudinally extending cylinder segments, means for displacing the segments into workpiece engaging position and means for displacing the segments into workpiece disengaging position.
  • FIG. 1 is a partial perspective view of an apparatus for deforming according to the method of the invention
  • FIGS. 2a, b and c are cross-sectional elevational views through the plane 2-2 of FIG. 1;
  • FIG. 3 is a key plan showing the figure relationship for considering FIGS. 2a, b and FIG. 4a is a partial elevational, cross-sectional view of the upstream rod clamping device utilized in the apparatus of FIG. 1;
  • FIG. 4b is a partial elevational, cross-sectional view of the downstream rod clamping device utilized in the apparatus of FIG. 1;
  • FIG. 5a is a partial cross-sectional view through the plane 5a5a of FIG. 4a;
  • FIG. 5b is a partial cross-sectional view through the plane Sb-Sb of FIG. 4b;
  • FIG. 6a through h are schematic views of the apparatus of FIG. 1 showing various relative motions and apparatus positions during the operation of the apparatus of FIG. 1;
  • FIG. 7 is a timing chart showing the position, velocity and pressure condition of various elements and systems of the apparatus of FIG. 1 during operation.
  • an extrusion apparatus for practicing the method of the invention is designated generally by the reference numeral 10.
  • a rod 12 of indefinite length continually passes into the upstream end of apparatus 10 wherein it is continuously extruded by a deforming agency and discharged as an extrusion product, e.g., wire 14, at the downstream end of the apparatus.
  • the rod 12 passing into apparatus 10 passes initially through an aperture 15 (FIG. 2a), having a sizing die surface 16, in a rigidly mounted base 17.
  • Sizing die surface 16 provides a means for correcting any oversize faults in rod 12 as it passes into apparatus 10.
  • Base 17 defines a rigid mounting means for a stationary clamp support pedestal 19 and a pair of fluid motors 20, 21 which cooperate to provide reciprocating motion to the upstream portion 22 of a reciprocating clamp cylinder, designated generally by the reference numeral 23, through rods 24 and 25 respectively.
  • reciprocating clamp cylinder 23 comprises an upstream portion 22 and a downstream portion 28 which extend slidably through a pressure vessel designated generally by the reference numeral 30.
  • Pressure vessel 30 comprises an upstream block 32, an intermediate block 33, and a downstream block 34.
  • Upstream block 32 and intermediate block 33 are disposed coaxially and joined by a securing ring 29.
  • intermediate block 33 and downstream block 34 are disposed coaxially and joined by a securing ring 36.
  • Extending through securing rings 29 and 36 are a plurality of support fluid supply lines 31 and extrusion supply lines 37, respectively.
  • Rods 40 and 41 connect the downstream portion 28 of reciprocating clamp cylinder 23 to a pair of fluid motors 42, 43 which cooperate with fluid motors 20 and 21 to provide reciprocating motion to the downstream portion 28 of reciprocating clamp cylinder 23.
  • Fluid motors are provided at each end of clamp cylinder 23 so that the reciprocating of the clamp may be accomplished while maintaining the cylinder in a state of compression.
  • the axial stresses generated in cylinder 23 during the operation of apparatus 10 may become of sufficient magnitude to exceed the tensile yield strength of the cylinder material.
  • opposed fluid motors 20, 21 and 42, 43 generate a compressive prestress in cylinder 23, which pro-stress enables cylinder 23 to be stressed in tension during the operation of the apparatus 10 without a resultant failure in the cylinder.
  • a ram 45 Extending slidably through an opening 44 in connector head 39 is a ram 45 which is secured to a piston rod 47 by a coupling 48 having an aperture 50 therein for allowing the discharge of wire 14.
  • Piston rod 47 is connected to a fluid motor (not shown) for imparting reciprocating movement to ram 45 within the downstream portion 28 of cylinder 23.
  • pressure vessel 30 can be seen to comprise upstream block 32, intermediate block 33 and downstream block 34 which are secured in spaced coaxial relationship by threaded securing rings 29 and 36.
  • Intermediate block 33 and downstreamblock 34' are provided with coaxial, longitudinally axially extending throughbores 55 and 56, respectively, which cooperate with an aperture 57 in upstream block 32 to define a bore extending through pressure vessel 30 for slidably accommodating reciprocating clamp cylinder 23 therein.
  • clamp cylinder 23 comprises an upstream portion 22 and a downstream portion 28. The two portions are joined at a threaded mating joint 52.
  • the diameter of aperture 57 in upstream block 32 is substantially equal to the outside diameter of the upstream portion 22 of clamp cylinder 23. Further, the downstream surface of aperture 57 is tapered to define an annular recess to accommodate the mounting therein of a high pressure seal structure 59. Seal structure 59 is shown to comprise an O-ring soft seal and an anti-extrusion ring. it should be recognized, however, that any high pressure seal structure which is suited for use in sealing the space between relatively movable surfaces may be used. 1
  • the downstream portion 28 of clamp cylinder 23 is provided with a stepped outer surface having a downstream portion 61, the diameter of which is substantially equal to the diameter of throughbore 56, and an upstream portion 63, the diameter of which is substantially equal to the diameter of throughbore 55.
  • Downstream surface portion 61 and upstream surface portion 63 are longitudinally separated by a relieved portion 65, the diameter of which is discussed below in detail.
  • the shoulders defined by the junctures of relieved portion 65 with downstream surface portion 61 and upstream surface portion 63 are shaped to accommodate the mounting of high pressure seals 67 and 68, respectively.
  • annular extrusion fluid distribution ring 70 Mounted coaxially with and between intermediate block 33 and downstream block 34 is an annular extrusion fluid distribution ring 70. Both the upstream and downstream radial surfaces 72, 73 'of ring 70 are provided with first relieved portions 75, I 76 which cooperate with annular shoulders formed on the corners of blocks 33 and 34 to define annular spaces for receiving high pressure seals 78 and 79 respectively. Spaced radially inwardly of first relieved portions75, 76 are second relieved portions 81, 82 which define annular spaces into which extrusion fluid may be discharged as is discussed below.
  • extrusion fluid distribution ring 70 is provided with an annular channel for mounting an O- ring seal 84, which seal precludes the passage of fluid between the inner surface of ring 70 and the surface of relieved portion 65 of the downstream portion 28 of clamp cylinder 23.
  • the upstream surface 63 of the downstream portion of clamp cylinder 23 is relieved at its upstream end and cooperates with the upstream portion 22 of cylinder 23 to define an annular space for receiving a high pressure seal 85.
  • the outercircumferential surface of upstream portion 22 cooperates with the surface of throughbore 55, seal 59 and seal 86 to define an annular outer chamber 90 for containing support fluid.
  • the surface of relieved portion 65 cooperates downstream of ring 70 with throughbore 56, seal 67 and second relieved portion 82 to define an outer annular extrusion fluid chamber 92.
  • relieved surface 65 cooperates with second relieved portion 81, throughbore 55 and seal 68 to define an annular clamp actuating fluid chamber 94.
  • Annular outer extrusion fluid chamber 92 and clamp actuating fluid chamber 94 vary in volume during operation of apparatus in that the longitudinal displacement of reciprocating clamp cylinder 23 causes relieved portion 65 to slide longitudinally back and forth within stationary ring 70.
  • Extrusion fluid is provided to fluid chambers 92 and 94 through passages formed in extrusion fluid distribution ring 70.
  • extrusion fluid source lines 37 pass radially inwardly through securing ring 36 at four positions around vessel 30.
  • the positioning and number of source lines 37 are arbitrary, however, in the apparatus 10, four lines are shown spaced at 90 intervals around ring 36.
  • Each orifice 96 communicates with an extrusion-fluid branch passage 98 and a clamping fluid branch passage 99 through a radially directed fluid passage 101.
  • Extrusion fluid branch passage 98 extends from passage 101 to the second relieved portion 82 of the downstream radial surface of ring so as to communicate outer extrusion fluid chamber 92 with a source of extrusion fluid (notshown) through passage 99 and fluid line 37.
  • Flow of fluid through branch passage 98 is limited by a spring ring check valve 103 which covers the opening of passage 98 into second relieved portion 82 in such a manner as to preclude flow of fluid out of chamber 92, and to limit the flow of fluid into chamber 92 to situations .wherein the pressure of the fluid in passage 98 is sufficient to overcome the spring load of ring check valve 103.
  • Clamping fluid branch passage 99 extends from passage 101 to the second relieved portion 81 of the upstream radial surface of ring 70 and provides for the unobstructed communication of clamp actuating fluid chamber 94 with a source of extrusion fluid (not shown) through passage 101 and fluid line 37
  • Extrusion fluid distribution ring 70 is maintained in position and supported radially by a segmented cylinder 104, which is in surface-to-surface engagement with the outer peripheral surface of ring 70.
  • Cylinder 104 is supported radially by bearing against the inner peripheral surface of securing ring 36.
  • Ring 107 is similar to extrusion fluid distribution ring 70 in that it is provided with relieved portions on its upstream and downstream radially extending surfaces to cooperate with annular shoulders on upstream and intermediate blocks 32, 33 to define annular channels for mounting high pressure seals 108 and 109 respectively. Further, ring 107 is provided with a plurality of radially extending passages 1 10 having conically relieved outer portions for receiving the tapered ends of supply lines 31. Ring 107 is maintained and supported radially by a segmented cylinder 111, bored plug 112 and a collar in the same manner discussed above with respect to ring 70.
  • a longitudinally axially extending bore 113 Formed through the major portion of the upstream portion 22 of clamp cylinder 23 is a longitudinally axially extending bore 113. Bore 113 communicates with the downstream end of portion 22 through a coaxial, longitudinally extending counterbore 114. Slidably received within bore 113 is generally cylindrical stationary clamp support pedestal 19. Support pedestal 19 is provided with a first bore 115 adjacent its downstream end for accommodating the mounting of a stationary rod clamping device, designated generally by the reference numeral 116, as is discussed in detail below, a second bore 118 of a diameter slightly larger than the diameter of rod 12 so as to provide for the free passage of fluid in an annular space 119 defined therebetween, and a third bore 120 the diameter of which is substantially equal to the diameter of rod 12. Annular space 119 provides for the introduction of clamp opening fluid to stationary rod clamp 116 from a fluid source (not shown) through a fluid supply line 122 and access passage 124.
  • the space bounded by the downstream end of stationary rod clamp 116, rod 12, bore 113, the upstream end of a reciprocable rod clamp designated generally by the reference numeral 130, and counterbore 114 defines an inner support fluid chamber 126 which is in communication with outer support fluid chamber 90 through a plurality of radially extending passages 127.
  • the diameter of counterbore 112 is somewhat larger than the diameter of rod 12 so as to allow the passage of support fluid through the annular space defined thereby, which fluid acts as a clamp opening fluid for reciprocable rod clamp 130.
  • the downstream portion 28 of reciprocating clamp cylinder 23 is provided with a first bore 132 which extends longitudinally axially from the upstream end thereof to a second longitudinally axial bore 133 which is smaller in diameter than first bore 132. Bore 133, in turn, extends from first bore 132 to a third bore 134 which comprises a continuation of opening 44 in enlarged head 39 (FIG. 1) and which extends throughout the major length of portion 28.
  • First bore 132 is provided with a first threaded surface for cooperating with upstream portion 22 to define threaded mating joint 52.
  • a second threaded surface is provided in first bore 132 to accommodate the mounting of reciprocable rod clamp 130 therein.
  • a fluid control element 136 Slidably received in second bore 134 is a fluid control element 136 which is mounted on the upstream end of ram 45 for reciprocating movement therewith. Fluid control element 136 is mounted on the end of ram 45 by a threaded mating connection 138.
  • downstream portion 28 of reciprocating clamp cylinder 23 is made in sections and joined by a threaded mating joint 139. A portion of the inner surface of downstream portion 28 is relieved adjacent mating joint 139 so as to accommodate the mounting of a high pressure seal 140 which is secured in position by a threaded retaining cylinder 141.
  • Seal precludes the flow of fluid out of an inner extrusion nicates at its downstream end with an axially extending passage 143 formed in fluid control element 136 and ram 45 to accommodate the discharge of extrusion product from the fluid control element, through ram 45 and out aperture 50 in coupling 48.
  • the deformation of rod 12 occurs as a result of pressures applied thereto by fluid flowing between the surface of the rod and flow control surface 137.
  • the axial length of flow control surface 137 defines a zone of deformation wherein occurs the deformation of rod 12 in producing wire 14.
  • thin-walled cylinder 144 Mounted in second bore 133 of the downstream portion 28 of reciprocating clamp cylinder 23 is a thinwalled cylinder 144, the inner diameter of which is the same as the diameter of third bore 134.
  • Thin-walled cylinder 144 is provided with a plurality of apertures which are positioned to be misaligned with a plurality of longitudinally and radially spaced ports 145 formed in downstream portion 28. Ports 145 provide for the communication of outer extrusion fluid chamber 92 with inner extrusion fluid chamber 142 through the apertures in thin-walled cylinder 144.
  • thin-walled cylinder is manufactured from a relatively flexible material such as berylium copper so as to act as a check valve.
  • FIG. 4a shows stationary rod clamp 116 in rod engaging position
  • FIG. 4b shows reciprocable rod clamp 130 in rod releasing position
  • FIG. 5a is a cross-sectional view through the plane 5a5a of FIG. 4a
  • FIG. 5b is a cross-sectional view through the plane 5b-5b of FIG. 4b.
  • stationary rod clamp 116 is shown positioned concentrically between the downstream portion 22 of reciprocating clamp cylinders 23 and rod 12.
  • the overall clamp structure includes an upstream sealing block 146 and a downstream sealing block 148 between which is positioned a rod clamping cylinder 150.
  • rod clamping cylinder 150 can be seen to be a segmented cylinder defined by a plurality of tapered segments 152.
  • Each segment 152 has an outer circumferential surface 154, an inner circumferential surface 155, and radially extending longitudinal surfaces 156 and 157 (FIG. 5).
  • each of radial surfaces 156 and 157 are provided with complementary, trapezoidally shaped channels 159, 160 which cooperate to define a seal receiving channel 161.
  • Each of channels 161 contains a pair of cross-sectionally triangular anti-extrusion strips 163, 164 which are separated by a strip 165 of circular cross-sectional sealing material.
  • Each radial surface 157 is also provided with a longitudinally extending channel which cooperates with the radial surface 156 of a next-adjacent segment 152 to define a clamp opening fluid passage 168 as is discussed in detail below.
  • the inner circumferential surfaces 155 of segments 152 when considered collectively, i.e., as the inner circumferential surface 172 (FIGS. 4a and b) of rod clamping cylinder 150, define a surface for positively engaging and gripping rod 12.
  • surface 172 is provided with shallow teeth 173 which, when the clamp segments 152 are in rod engaging position (FIG.
  • An additional function of shallowteeth 173 is to provide an axial stress gradient in the material of rod 12 when either of clamps 116 or 130 is engaged.
  • the operation of apparatus generates axial stress in rod 12 between the zone of deformation in fluid control element 136 and whichever of clamps 116 or 130 is supporting rod 12 at that time.
  • the teeth 173 of clamps 116, 130, when engaged with rod 12, each carry an incremental amount of the axial force on rod 12 generated by the deformation thereof through fluid control element 136, thereby reducing the axial stress in the rod.
  • the axial stress in rod 12 is gradually reduced, i.e., an axial stress gradient is established, along the length of rod 12 which is engaged by teeth 173.
  • Each upstream sealing block 146 comprises an annular ring having a generally rectangular cross-sectional configuration. Each ring is provided with a downstream surface 175, an upstream surface 176, an outer circumferential surface 177 and an inner circumferential surface 178. Downstream surface 175 is in surface-to-surface engagement with the upstream end of clamping cylinder 150 and is provided with a trapezoidally shaped annular channel for receiving a high pressure seal 180. Seal 180 is positioned adjacent seal receiving channel 161 and precludes the radial passage of fluid either radially inwardly or outwardly around the upstream ends of strips 163, 164 and 165.
  • Outer circumferential surface 177 is provided with a trapezoidally shaped annular channel for receiving a high pressure seal 182 which prevents the passage of fluid between the outer surface of sealing block 146 and the inner surface of first bore 1 15 (F 16. 4a) or first bore 132 '(FIG. 4b).
  • the inner surface 178 of block 146 is of a diameter substantially equal to the diameter of rod 12 to minimize the passage of fluid therebetween while allowing rod 12 to slide freely therethrough.
  • passages 183 Formed in-block 146 are a plurality of generally longitudinally extending passages 183 which provide for the communication of fluid from annular space 119 -(FIG. 4a) and counterbore 112 '(FIG. 4b) to fluid passages 168 in clamps 116 and 130 respectively. Passages 183, at their downstream end, communicate with an annular channel 185 formed in the downstream I surface of block 146. Provision of channel 185 obviates the necessity to align passages 183 in block 146 with passages 168 in cylinder 150, and insures that fluid communication between passages 183 and 168 is maintained.
  • the downstream sealing block 148 (FIG. 4a) associated with stationary sealing clamp 116 comprises an annular ring having upstream and downstream radial surfaces 187, 188, an outer circumferential surface 189 and an inner circumferential surface 190.
  • Outer surface 189 is provided with threads 192 on a portion of its length, which threads cooperate with threads on the inner surface of first bore to secure block 148 in position against rod clamping cylinder 150.
  • the upstream surface of 187 of block 148 is provided with an annular trapezoidal channel for receiving a high pressure seal 194 which, in the same manner as seals in blocks 146, prevents leakage of fluid around the ends of strips 163,164, 165 in seal receiving channel 161. 6
  • annular channel 196 Inner circumferential surface of block 148 is relieved to define an annular channel 196 in which an annular sealing ring 197 is positioned.
  • the unrelieved portion of surface 190 is of a diameter slightly smaller than rod 12 to provide surface-to-surface contact seal between block 148 and rod 12 the purpose of which is discussed in detail below.
  • Formed in the surface of annular channel 196 is a smaller annular channel 199 to which there extends, from downstream surface 188, a
  • channel 199 is in communication with an annular channel 202 formed in first bore 1 15 through a plurality of passages 204.
  • Free communication between channels 196 and 199 is prevented by a spring ring check valve 206 which permits fluid to pass from channel 199 to channel 196, but only when the pressure of fluid in channel 199 is sufficient to deflect spring ring 206.
  • reciprocable rod clamp 130 can be seen to comprise a rod clamping cylinder 150 positioned between an upstream sealing block 146 and a downstream sealing block 208.
  • Downstream sealing block 208 is of the same general configuration as downstream sealing block 148 discussed above with the exception that block 208 is secured against a shoulder 210 defined at the intersection of first bore 132 with second bore 133, both in the downstream section 28 of clamp cylinder 23, and thus the outer surface of block 208 is not threaded.
  • Block 208 is provided with upstream and downstream surfaces 212, 213, an outer circumferential surface 214 and an inner circumferential surface 215.
  • Upstream surface 212 of block 208 is in surface-to-surface engagement with the downstream end of clamping cylinder 150 and is provided with a trapezoidally shaped annular channel for receiving a high pressure seal 217.
  • Seal 217 is positioned adjacent seal receiving channel 161 and precludes the radial passage of fluid, either radially inwardly or outwardly around the downstream ends of strips 163, 164 and 165.
  • outer circumferential surface 214 is provided with a trapezoidally shaped annular channel for receiving a high pressure seal 218 which prevents the passage of fluid between the outer surface 214 of sealing block 208 and the inner surface of first bore 132 (FIG. 4b).
  • Inner circumferential surface 215 of block 208 is relieved to define an annular channel 220 in which is positioned an annular sealing ring 197 which is the same as ring 197 discussed above with respect to FIG. 4a.
  • the unrelieved portion of surface 215 is of a diameter slightly smaller than rod 12 to provide a surface-tosurface contact seal between block 208 and rod 12.
  • Formed in the peripheral surface of annular channel 220 is an annular channel 222 which is in connection with an annular channel 224 formed in the surface of first bore 132 through a plurality of fluid passages 225.
  • Free communication between channels 220 and 222 is prevented by a spring ring check valve 227 which permits fluid to pass only from channel 222 to channel 220, and then only when the pressure of fluid in channel 222 is sufficient to deflect spring ring 227.
  • Annular sealing rings 197 may be formed of resilient material such as rubber and are provided with a tapered surface on their upstream ends which complements and is engageable with a tapered surface in annular channel 220.
  • the outer circumferential surface and downstream surface of annular sealing ring 197 are provided with relieved portions which define passages 229 for the accommodation of fluid therethrough.
  • the inner diameter of annular sealing ring 197 is substantially equal to the diameter of rod 12 so as to allow the sliding passage of rod 12 therethrough when seal 197 is not under load so as to be in sealing engagement with rod 12 as is discussed in detail below.
  • clamps 116 and 130 are best considered with reference to FIGS. 2a, 2b, 4a, 4b, 5a and 5b. More specifically, each of clamping cylinders 150 are subjectable to two distinct bodies of fluid, viz. a body of clamp closing fluid which bears against the outer surface 170 of rod clamping cylinder 150 which tends to displace segments 152 radially inwardly, and a clamp opening fluid which is circulated within cylinder 150 through passages 168 and which tends to displace segments 152 radially outwardly.
  • FIG. 5a which shows clamping cylinder in rod engaging position
  • clamp opening fluid is present in passages 168 and tends to displace segments 152 radially outwardly.
  • Clamp closing fluid is provided within passages 158 and circulating around the threaded outer surface so as to bear against the outer surface 170 of clamping cylinder 150, thereby tending to displace segment 152 radially inwardly.
  • the clamp closing fluid is at a pressure sufficiently greater than the clamp opening fluid to overcome the effect of the clamp opening fluid thereby causing segments 152 to be displaced radially inwardly so as to cause the engagement of shallow teeth 173 with the surface of rod 12.
  • the pressure of the fluid in channels 168 is made to be such, either by increasing the clamp opening fluid pressure or decreasing the clamp closing fluid pressure, that the force generated thereby is in excess of the force generated by the effect of clamp closing fluid against outer surface 170.
  • segments 152 are displaced radially outwardly away from rod 12 from the position shown in FIGS. 4a and 5a to the position shown in FIGS. 4b and 5b, and rod release occurs.
  • the bodies of clamp opening fluid and clamp closing fluid are maintained distinct by the high pressure seal structure provided in seal receiving channels 161. More specifically, and considering only one of the seal structures, when clamping cylinder 150 is in open position, the clamp opening fluid circulates from channel 168 radially outwardly between segments 152 to bear against the tapered surfaces of anti-extrusion strip 164. Strip 164 in turn bears against sealing strip 165 which in turn bears against anti-extrusion strip 163. The tapered surfaces of anti-extrusion strip 163 are thereby forced against the complementarily tapered surfaces of channels 159 and 160 formed in the surface of segments 152 as discussed above. This engagement effects a fluid tight seal which prevents the clamp opening fluid from coming into communication with the clamp closing fluid.
  • the pressure of clamp closing fluid is increased with respect to the pressure of clamp opening fluid, either by increasing the clamp closing fluid pressure or by decreasing the clamp opening fluid pressure, so as to displace segments 152 radially inwardly.
  • clamp closing fluid pressure exceeds clamp opening fluid pressure
  • anti-extrusion strip 163 is forced out of engagement with the tapered surfaces of seal receiving channel 161 and the tapered surfaces of anti-extrusion strip 164 are causes to engaged the tapered surfaces of seal receiving channel 161.
  • This engagement once again effects a seal which prevents the communication 158 (FIG. 5) which are in communication at their upstream ends with annular channel 202.
  • the support fluid from support fluid chamber 126 also acts as clamp opening fluid for reciprocable rod clamp 130.
  • fluid in chamber 126 is in communication with passages 168 in clamp 130 through counterbore 112 and passage 183 in upstream sealing block 146.
  • Clamp closing fluid is provided to clamp 130 from extrusion fluid supply line 37, through passages 101 and 99 into clamp closing fluid chamber 94, and thereafter through an access passage 95 to passages 158 along the outer surface 170 ofthe clamp.
  • fluid pressure is continually maintained in the extrusion fluid which acts as clamp closing fluid for reciprocable rod clamp 130, and upon the clamp opening fluid acting upon stationary rod clamp 116.
  • the pressure of the fluid in support fluid chamber 126 is varied cyclically.
  • stationary rod clamp 116 is anorrnally open clamp which closes only upon the increase of pressure in the support fluid in chamber 126.
  • the constant exertion of clamp closing pressure and the intermittent of the clamp closing fluid with the clamp opening fluid because of the constant exertion of clamp closing pressure and the intermittent of the clamp closing fluid with the clamp opening fluid.
  • clamp opening fluid is provided to fluid passages 168 thereof from a source (not shown) through supply line 122 and passage 124 into annular space 119 whereupon it passes between the surface of rod 12 and second bore 118 to fluid passage 183 and channel 185 in upstream sealing block 146.
  • Clamp closing fluid for stationary rod clamp 116 is provided from inner support fluid chamber 126, through passage 201, channel 199 and passage 204 (FIG. 4a) in downstream sealing block 148 to annular channel 202. Thereafter, clamp closing fluid is circulated to the outer circumferential surface 170 of clamping cylinder 150 through passages exertion of clamp opening pressure reciprocable rod clamp is a normally closed clamp which opens only upon the increase of pressure in the support fluid in chamber 126.
  • the operation of the apparatus of FIGS. 2a, b and 0 comprises the steps of establishing and maintaining a desired relative velocity of a workpiece, e.g., rod 12, against a deforming agency comprising a flow of pressurized fluid through fluid control element 136, and continuously deforming the rod against the deforming agency to produce product 14.
  • the desired relative velocity between the deforming agency and the rod is accomplished by intermittently advancing the rodagainst the deforming agency, intermittently advancing the deforming agency over-the rod, and coordinating the intermittent advance of the rod with the intermittent advance of the deforming agency to maintain a desired relative velocity therebetween so as to maintain a continuous positive fluid flow extrusion of the rod.
  • the relative speed of rod 12 passing through fluid control element 136 is maintained such as to effect and maintain an extrusion equilibrium condition so as to maintain extrusion at a desired product discharge rate.
  • the specific mode of extrusion in operating the apparatus of FIGS. 2a, b and c is that of positive fluid flow extrusion.
  • This mode of extrusion contemplates establishing a positive flow of pressurized fluid through a .fluid control element while concurrently passing material to be deformed through the fluid control element within the flowing fluid.
  • the pressurized flowing fluid exerts pressures on the material passing therewith through the fluid control element, which pressures bear upon the material to accomplish the deformation thereof.
  • the extrusion equilibrium condition referred to above connotes the situation during extrusion when (a) a constant relative velocity of advance of rod 12 is occurring through fluid control element 136 notwithstanding variations in the magnitudes of their absolute velocities, (b) stresses generates in rod 12 by the effect of fluid bearing against the surface thereof in cooperation with the mechanical forces exerted thereon by clamps 116 and 130 are such as to accomplish deformation of the material as desired within fluid control element 136, (c) a controlled flow of fluid is passing through fluid control element 136 so as to exert deformation pressures on the material passing therethrough, and (d) deformation is occurring with wire 14 being discharged through passage 143 and aperture 50 at a desired rate.
  • volumes of product 14 and extrusion fluid are discharged through fluid control element 136 in constant proportion and equal in total volume to the volume of the relative incremental displacement of rod 12 and its surrounding fluid through fluid control element 136.
  • deformation of the material of rod 12 is accomplished by the exertion of pressure against the material being deformed by fluid flowing through fluid control element 136.
  • the pressure of the fluid flowing through the zone of deformation of fluid control element 136 decreases in the direction of flow while at the same time remaining at sufficient magnitude to maintain the material in a deformation state throughout the zone of deformation.
  • Such a deformation state exists within the zone of deformation when the radial stress in the material exceeds the axial stress in the material by an amount at least equal to the yield stress of the material.
  • Control of the rate of decrease of the pressure of fluid flowing through the zone of deformation so as to maintain the stress relationship desired for deformation is accomplished by providing fluid control element 136 with flow control surface 137, which surface is shaped to define a controlled path for regulating fluid flow so as to achieve the desired pressure regulation.
  • the shape of the flow control surface may be linear or nonlinear, and may be determined empirically as is disclosed in the above-noted copending application for METHOD OF POSITIVE FLUID FLOW EXTRU- SION.
  • FIGS. 2a, b, and c accomplishes the above discussed positive fluid flow extrusion with respect to the extrusion of a continuous rod of indefinite length to accomplish the production of a continuous extrudant also of indefinite length, such as wire.
  • the continuity of the extrusion is accomplished by providing a reciprocating extrusion cycle, one phase of which comprises advancing fluid control element 136 axially along rod 12 to effect its extrusion, and a second phase of which comprises advancing rod 12 through fluid control element 136 during retraction thereof, in such a manner as to maintain a constant relative rate of advance of rod material and fluid through the fluid control element at all times during the cycle, including those times when the cycle is shifting from the one phase to the second phase, and thereafter from the second phase back to the one phase.
  • various operational movements are required of the apparatus elements, viz.
  • FIGS. 6a through h The operational positions of the various apparatus components during extrusion are set out schematically in FIGS. 6a through h which, when considered in conjunction with the timing chart of FIG. 7, provides a better understanding of the operation of the apparatus 10.
  • all systems of the apparatus are filled with fluid and a rod 12 is positioned within the apparatus by passing the head end thereof through the aperture 15 in base 17 and thereafter advancing the rod axially until it has passed through clamps 116 and and extends within inner extrusion fluid chamber 142.
  • the apparatus 10 can be started at virtually any point in its cycle. Although a convenient position in the cycle to start the apparatus is shown in FIG. 6a wherein reciprocating the clamp cylinder 23 is in fully retracted position (fully to the right as seen in the figure), stationary clamp 116 is engaging rod 12, reciprocable clamp 130 is not in engagement with rod 12 and fluid control element 136 is in position to advance (move to right within chamber 142) over rod 12.
  • the head of rod 12 can be pre-shaped, for example in the manner disclosed and claimed in copending application for METHOD OF PREFORMING MATERIALS WHICH WORK HARDEN, Ser. No. 758,732, filed Sept. 10, 1968 and assigned to the same assignee as the present applica tion.
  • preshaping while advantageous, is not necessary and apparatus 10 can be operated whether the head of rod 12 is preshaped or not.
  • fluid controlelement 136 causes a flow of fluid out of inner extrusion fluid chamber 142 and through the fluid control element 136 and passage 143 to be discharged through aperture 50.
  • the flow control surface 137 of fluid control element 136 approaches the head end of rod 12, the space between the head end of rod 12 and the flow control surface 137 decreases in size and progressively restricts the flow of fluid therethrough.
  • the flow restriction which in effect is a valving action, causes an increase in the pressure of the fluid in the vicinity of the head end of the billet.
  • the pressure drop in extrusion fluid flowing through fluid control element 136 is such as to insure that at all points along the zone of deformation, the stresses generated within the material are such as to cause the deformation thereof from the shape of rod 12 to that of product 14, i.e., at all points within the zone of deformation the net radial stress onthe material exceeds the net axial'stress by an amount equal to at least the yield stress of the material.
  • the rod material When radial stress exceeds axial stress by an amount equal to or greater than the yield stress of the material, the rod material is caused to sink, i.e., be displaced longitudinally axially. If, however, the axial stress exceeds the radial stress, the rod material will be displaced radially, i.e., bulge and tend to expand at the point of deformation.
  • rod 12 is subjected to relatively high radial and axial stresses during the operation of apparatus 10, provision is made to obviate the possibility of sinking or bulging of the rod material prior to its entrance into the zone of deformation of fluid control element 136.
  • FIG. 6a shows the apparatus configured and operating just after extrusion has commenced, i.e., fluid control element 136 is being advanced by ram 45, clamp 130 is open, clamp 116 is engaged and clamp cylinder 23 is fully retracted and stopped.
  • outer extrusion fluid chamber 92 is isolated from inner extrusion fluid chamber 142 (i.e., thin cylinder 144 is covering ports 145) and thus, the advance of fluid control element 136 into inner extrusion fluid chamber 142 causes fluid to be pumped therefrom through fluid control element 136.
  • each of the clamps 116 and 130 is operated from engaged to disengaged position by establishing a pressure differential between the pressures of the clamp opening and clamp closing fluids.
  • a pressure differential can occur at a relatively high pressure as well as a relatively low pressure level.
  • the support fluid acts as clamp closing fluid operating against the effect of the stationary clamp opening fluid supplied through line 122.
  • the clamp opening fluid for clamp 116 is maintained at a pressure which is less in magnitude than the pressure of the extrusion fluid provided through line 37.
  • the support fluid will overcome the relatively low pressure stationary clamp opening fluid pressure so as to close clamp 116 at a much lower pressure level than it can overcome the relatively high pressure extrusion fluid pressure so as to open clamp 130.
  • FIG. 6b represents the point in the extrusion cycle where support fluid pressure has dropped sufficiently to allow reciprocable rod clamp 130 to engage rod 12, fluid control element is advancing at an absolute velocity which is equal to the desired relative velocity for maintaining extrusion equilibrium, clamp 116 is still engaged and reciprocable clamp cylinder 23 is still in a stopped condition. This situation is shown in FIG. 7 as line b.
  • This coordination between the velocities of the rod and fluid control element is maintained at all times during extrusion by apparatus and is accomplished by coordinating the motive fluid provided to fluid motors 20, 21, 42 and 43 with the motive fluid provided to the fluid motor (not shown) which operates ram 45 through piston rod 47 (FIG. 1).
  • Such coordination may be accomplished by any of a plurality of known methods in the hydraulics art.
  • one of fluid motors 42 or 43 may have a servo valve connected thereto for reciprocation with the ram or piston of the fluid motor.
  • the servo valve may be driven in response to the movement of a cam mounted on a common rotating cam shaft, which cam may be shaped to establish movement of the reciprocating clamp in accordance with the value of reciprocating clamp velocity as shown in the timing chart of FIG. 7. Operation of the servo valve on fluid motor 42 in response to the positioning of the cam will control the flow of fluid into or out of both fluid motors 42 and 43.
  • the fluid motor (not shown) which operates ram 45 through piston 47 may also be provided with a servo valve which is actuated in response to the positioning of a cam mounted on the abovenoted common cam shaft. Operation of such a servo valve will control the flow of fluid into and out of the fluid motor and thus control the speed of advance and retraction of ram 45 and piston 47.
  • the cam for this fluid motor would be shaped in accordance with the curve of fluid control element velocity as shown in FIG. 7. Further, since both of the cams for operating the fluid motors are mounted on a common rotating cam shaft, the velocities and positions of the reciprocating clamp and fluid control element are positively controlled at all times during operation of the apparatus.
  • each of fluid motors 20 and 21 can be provided with a pressure regulating valve and suitable source of messurized fluid for maintaining a compressive force against reciprocating clamp cylinder 22 notwithstanding whether it is advancing or retracting.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Forging (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Extrusion Of Metal (AREA)
US862673A 1969-10-01 1969-10-01 Continuous material deformation process and apparatus therefor Expired - Lifetime US3696652A (en)

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US86267369A 1969-10-01 1969-10-01

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US (1) US3696652A (fr)
AU (1) AU2036570A (fr)
BE (1) BE756780A (fr)
CA (1) CA921864A (fr)
CH (1) CH529597A (fr)
ES (1) ES384475A1 (fr)
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GB (2) GB1324607A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4319476A (en) * 1978-07-19 1982-03-16 Western Electric Company, Incorporated Methods and apparatus for extrusion
US4425775A (en) 1978-07-19 1984-01-17 Western Electric Co. Methods for extrusion

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2586536A (en) * 1947-03-15 1952-02-19 Haller John Pressure fluid clamp
US3260084A (en) * 1962-05-02 1966-07-12 Ajax Mfg Co Apparatus for drawing linear stock
US3434320A (en) * 1966-02-04 1969-03-25 Atomic Energy Authority Uk Hydrostatic extrusion apparatus
US3440849A (en) * 1966-05-13 1969-04-29 Atomic Energy Authority Uk Hydrostatic extrusion apparatus
US3449935A (en) * 1965-09-17 1969-06-17 Nat Res Dev Apparatus and method of metal extrusion
DE1813402A1 (de) * 1967-12-11 1969-08-21 Asea Ab Anordnung und Verfahren zum kontinuierlichen hydrostatischen Strangpressen
US3520164A (en) * 1966-12-16 1970-07-14 Vickers Ltd High pressure extrusion apparatus
US3528269A (en) * 1967-03-03 1970-09-15 Asea Ab Method of extrusion with liquidpressure and means for carrying out the method
US3538730A (en) * 1966-09-21 1970-11-10 Nat Res Dev Extrusion method and apparatus

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2586536A (en) * 1947-03-15 1952-02-19 Haller John Pressure fluid clamp
US3260084A (en) * 1962-05-02 1966-07-12 Ajax Mfg Co Apparatus for drawing linear stock
US3449935A (en) * 1965-09-17 1969-06-17 Nat Res Dev Apparatus and method of metal extrusion
US3434320A (en) * 1966-02-04 1969-03-25 Atomic Energy Authority Uk Hydrostatic extrusion apparatus
US3440849A (en) * 1966-05-13 1969-04-29 Atomic Energy Authority Uk Hydrostatic extrusion apparatus
US3538730A (en) * 1966-09-21 1970-11-10 Nat Res Dev Extrusion method and apparatus
US3520164A (en) * 1966-12-16 1970-07-14 Vickers Ltd High pressure extrusion apparatus
US3528269A (en) * 1967-03-03 1970-09-15 Asea Ab Method of extrusion with liquidpressure and means for carrying out the method
DE1813402A1 (de) * 1967-12-11 1969-08-21 Asea Ab Anordnung und Verfahren zum kontinuierlichen hydrostatischen Strangpressen

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4319476A (en) * 1978-07-19 1982-03-16 Western Electric Company, Incorporated Methods and apparatus for extrusion
US4425775A (en) 1978-07-19 1984-01-17 Western Electric Co. Methods for extrusion

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Publication number Publication date
GB1324607A (en) 1973-07-25
ES384475A1 (es) 1973-03-16
FR2068270A5 (fr) 1971-08-20
AU2036570A (en) 1972-03-30
BE756780A (fr) 1971-03-01
GB1324610A (en) 1973-07-25
CA921864A (en) 1973-02-27
CH529597A (de) 1972-10-31

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