US3631706A - Methods of and apparatus for forming an article having a tubular portion - Google Patents

Methods of and apparatus for forming an article having a tubular portion Download PDF

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US3631706A
US3631706A US802040A US3631706DA US3631706A US 3631706 A US3631706 A US 3631706A US 802040 A US802040 A US 802040A US 3631706D A US3631706D A US 3631706DA US 3631706 A US3631706 A US 3631706A
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die
billet
mandrel
punch
forming
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John Wesley Archer
Francis Joseph Fuchs Jr
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AT&T Corp
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Western Electric Co Inc
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Assigned to AT & T TECHNOLOGIES, INC., reassignment AT & T TECHNOLOGIES, INC., CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). EFFECTIVE JAN. 3,1984 Assignors: WESTERN ELECTRIC COMPANY, INCORPORATED
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
    • B21J5/02—Die forging; Trimming by making use of special dies ; Punching during forging
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor

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  • This invention is related broadly to methods of and apparatus for forming articles; and in particular, to methods and apparatus for forming articles having tubular portions, such as cup-shaped articles, from billets of solid plastic material.
  • the cup-shaped articles which may be formed by the practice of the present invention may be of circular transverse cross-sectional configuration, or otherwise such as of elliptical, polygonal or irregular cross-sectional configuration.
  • the wall thickness of such cup-shaped articles may be uniform or y
  • solid plastic material it is known by those skilled in the art, that many metals and other materials increase in ductility, or have an increased capacity for deformation without fracture, when they are subjected to high pressure. These metals and other materials are known as solid plastic materials. This principle is treated in P. W. Bridgman, Large Plastic Flow and Fracture, published by McGraw-I-lill Book Company of New York in 1952. Accordingly, it will be understood that the expression solid plastic material as used in this specification and claims, is used in this context. I
  • cupshaped articles include machining processes, extrusion processes and deep drawing processes. The choice of one of these particular processes from among the others is ordinarily determinable from the required dimensions of the article to be formed and the characteristics of the material from which the article is to be manufactured.
  • Machining processes which do not involve the deformation of material, and which, therefore, have been utilized in situations wherein manufacture by deformation processes has been rendered at least commercially infeasible, are disadvantageous in that they are extremely time consuming and expensive. Thus, those having skill in this art recognize that, if at all possible, machining processes should not be utilized if manufacture can be satisfactorily accomplished by deformation processes.
  • deep drawing processes for forming cup-shaped articles is limited to the manufacture of cupshaped articles the wall thicknesses of which are not less than to 20 percent less than the original thickness of the material being deformed.
  • deep drawing processes ordinarily comprise the positioning of a blank of material over a die having an opening, the inside diameter of which opening conforms to the desired outside diameter of the cup-shaped article to be formed, and thereafter advancing a plunger against the blank and into the die opening so as to draw the blank material into the die opening to form the desired cupshaped article.
  • the outside diameter of the plunger corresponds to the desired inside diameter of the cup-shaped article to be fonned and therefore the plunger and die opening cooperate to define the wall thickness of the article being formed.
  • This wall thickness ordinarily has been limited to be no less than 10 to 20 percent thinner than the thickness of the original blank, or, in terms of the structure of the cup-shaped article being formed, the thickness of the cup wall portion can be no more than 10 to 20 percent thinner than the thickness of the base portion.
  • sucha limitation restricts the availability of deep drawing as a process for manufacturing cup-shaped articles which desirably have wall portions which are thinner than percent of the thickness of the base portion.
  • Extrusion processes for fonning cup-shaped articles have been utilized for many years. Ordinarily, such processes are single operation processes which comprise positioning of a bi]- let of material within the opening of a cylindrical die, the inside diameter of which corresponds to the outside diameter of the cup-shaped article being formed. One end of the billet is then supported within the die and the other end of the billet is subjected to a deforming force by a punch which is advanced thereagainst. The outside diameter of the punch corresponds to the inside diameter of the cup-shaped article to be formed.
  • the billet material in line with the path of advance of the punch is displaced laterally toward the surface of the die and thereafter longitudinally between the punch and the die to become the wall portion of the article being formed.
  • the cylindrical die was held stationary and the billet material was caused to flow between the die surface and the surface of the advancing punch in such manner as to generate relative movement between the material undergoing deformation and the surfaces of both the die and the punch.
  • Such relative movement required that the working forces applied to the material in deformation be sufficiently high to overcome the friction generated between the material in deformation and both the plunger surface and the die surface.
  • the total force applied to the material in deformation was required to be that necessary not only to deform, but to overcome the abovenoted frictional forces.
  • machining processes for manufacturing cup-shaped articles have been resorted to in those manufacturing situations wherein drawing is not appropriate and wherein the use of extrusion processes for the formation of tubular or cup-shaped articles is because the amount of deformation required would cause the fracture point of the material to be exceeded prior to the completion of the forming process.
  • machining processes are extremely complex and therefore expensive.
  • a typical machining process for manufacturing a cup-shaped article from bar stock ordinarily includes the steps of drilling the stock to form a rough cup cavity, turning the outside diameter of the workpiece to exact dimension, boring the rough cup cavity to form a finished cup cavity, cutting the workpiece to appropriate length, deburring, and cleaning the machined article.
  • the present invention overcomes the disadvantages noted above with respect to the prior art processes by providing a method and apparatus for forming articles, which method and apparatus are not limited by the ductility of the material, i.e. the ductility under atmospheric conditions. Specifically, by not being so limited, the method and apparatus of the present invention enable the formation of articles having tubular portions, such as cup-shaped articles, from billet material by a single manufacturing process, which articles heretofore have been capable of manufacture only by machining processes.
  • the process of he present invention may include the steps of confining a quantity of material in a die system including an outer die, a punch, and a mandrel which together define an enclosed die cavity; moving dies of said die system to pressurize said material and moving said outer die and mandrel relatively, while maintaining said die cavity constant in volume and the blank pressurized, to produce said article.
  • Apparatus in accordance with the present invention may include die means for defining an enclosed variable shape die cavity; and means engaging said die means for (i) varying the shape of said die cavity to initially confine and pressurize a quantity of material and, thereafter (ii) varying the shape of said die cavity while maintaining the volume thereof constant to deform said material to form said article while maintaining said material confined and pressurized.
  • FIGS. 1A, B and C are cross-sectional elevational views of a basic apparatus according to the present invention, the views showing the apparatus during progressive steps of the inventive method;
  • FIG. 2 is a cross-sectional elevational view of a novel apparatus for practicing the method of the present invention, the apparatus being shown in position for receiving a blank prior to deformation;
  • FIG. 3 is a view similar to that of FIG. 2 but with the apparatus shown in position for the commencement of blank deformation;
  • FIG. 4 is a view similar to that of FIG. 2 but with the apparatus shown at the completion of the deformation step;
  • FIG. 5 is an exploded, partial cross-sectional perspective view of the segmented die of the apparatus of FIGS. 24.
  • FIG. 1 wherein apparatus designated generally by the reference numeral 10, is shown in three stages (FIGS. 1A, 1B and 1C) of the process of the present invention for manufacturing a cup-shaped article.
  • a generally cylindrical outer die section 12 is mounted for controlled, longitudinal reciprocation by suitable means (not shown).
  • Outer die section 12 is provided with a first bore 14 which defines a die bore and extends from the upper surface of outer die section 12 axially through a portion thereof, and a second bore 15 which is coaxial with die bore 14 and extends from the lower surface of outer die section 12 to communicate with die bore 14.
  • the diameter of the die bore 14 corresponds to the desired outside diameter of the cup-shaped article to be formed
  • the diameter of the second bore 15 corresponds to the diameter of the opening or cavity to be formed in the cup-shaped article.
  • the intersection of die bore 14 with the second bore 15 defines a radially extending shoulder 16 which is substantially equal in width to the wall thickness of the cup-shaped article to be formed.
  • die bore 14 The upper end of die bore 14 is closed by a reciprocable ram 17 which is of a diameter substantially equal to and slidably received within thedie bore 14.
  • a reciprocable ram 17 Rigidly secured to a suitable support means 20, and slidably received within second bore 15 is a mandrel or inner die section 19, the diameter of which, and the conical leading end 21 of which, are shaped to define the desired configuration of the cavity of the cup-shaped member to be formed.
  • die cavity 22 for receiving therein a quantity of material such as a billet 23 of solid plastic material, to be deformed. Because the outer die section 12 and ram 17 are both movable with respect to mandrel or inner die section 19, die cavity 22 comprises a die cavity the shape of which is variable.
  • the first step of the operation of the apparatus in accordance with the method of the invention comprises positioning a billet 23 within variable shape die cavity 22.
  • ram 17 is advanced (moved downwardly as seen in FIG. 1) within die bore 14 against billet 23 so as to cause deformation of the billet material around the conical leading end 20 of mandrel 19.
  • ram 17 is advanced from the position shown in FIG. 1A to the position shown in FIG. 18 so as to vary the shape of die cavity 22.
  • Variation of the shape of die cavity 22 in this manner causes the billet material to completely fill or be confined by die cavity 22.
  • the amount of deformation experienced in filling the die cavity 22 in the manner shown, i.e. by advancing ram 17 against billet 23, is well within the limits of the ductility at atmospheric pressure or ordinary deformation capability of the materials.
  • brittle materials which at atmospheric pressure, have a ductility limit or fracture point which is less than that required even for defonning the billet to fill the die cavity with blank material.
  • the confined material can be pressurized so as to increase, if required, its ductility or capability for deformation without fracture.
  • ram 17 With the billet 23 confined within variable shape die cavity 22 as shown in FIG. 18 continued pressure is exerted by ram 17 against the confined billet material.
  • the pressure exerted by ram 17 is of sufficient magnitude to increase the ductility of the billet material from that which is ordinarily characteristic of the material at atmospheric pressure, to that ductility which is required to accomplish the necessary deformation for cupshaping without resulting in fracture.
  • the final deformation of the billet 23 can be undertaken.
  • both the outer die section 12 and ram 17 are advanced concurrently from the position shown in FIG. IE to the position shown in FIG. 1C so as to vary the shape of die cavity 22 from that corresponding to the shape of confined billet 23 to that corresponding to the desired shape of cup-shaped article 26.
  • die 12 is advanced longitudinally axially through a distance equal to the length of the walls of the cup-shaped article to be formed.
  • concurrent advance of ram 17 and cylindrical die 12 is coordinated to maintain the volume of die cavity 22 constant, i.e.
  • the exertion of pressure on billet 23 to increase the ductility of the solid plastic material thereof and to accomplish the deformation thereof from the billet shape of FIG. 18 to the cup shape of FIG. 1C can be accomplished in more than one manner. More particularly, in apparatus such as that shown in FIG. 1, the surface of die bore 14 is a smooth surface and, as a practical matter in the light of the pressures experienced during deformation, the die bore surface generates little, if any longitudinally directed forces. Thus, the entire force necessary to establish the high pressure required to adequately increase the ductility of the billet material and that force necessary to stress the pressurized billet material to accomplish deformation, must be exerted by ram 17 alone.
  • outer die section 12 serves solely to enable the controlled variation of the shape of variable shape die cavity 22.
  • the surface die bore 14 may be provided with a textured or otherwise roughened surface, for example the threaded surface of die bore 129 of the apparatus 40 of FIGS. 24.
  • the high friction surface of the die bore is capable of exerting axially directed forces on the billet material which can assist ram 17 in stressing the billet material during the deformation thereof from billet shape to cup shape.
  • the load on the ram is decreased and a more intimate engagement between the outer die section and the billet material is established, which engagement facilitates a closer control of the shape of the variable shape die cavity.
  • ram 17 is retracted (moved upwardly as seen in FIG. 1), outer die section 12 is retracted to free article 26 from mandrel l9, cup-shaped article 26 is removed from the apparatus and a new billet 23 is positioned within die 12 in preparation for repeating the process.
  • the advantages offered by the method and apparatus of the present invention as described above include the substantial elimination of relative movement between the billet material and the surface of die bore 14, and the capability of confining, prepressurizing and maintaining pressurized during deformation of the billet material so as to increase its ductility or capability for deformation without fracture, thereby facilitating the manufacture of cup-shaped articles which heretofore could only be manufactured by machining.
  • the basic apparatus disclosed in FIG. 1 includes inner die or mandrel 19 as a fixed element, with outer die section 12 and a ram 17 as movable elements.
  • the purpose of providing two elements of the three part die structure with a capability for movement, is to provide a die having a variable shape die cavity wherein relative movement between the billet material and the surface of one element, viz the die bore of outer die section 12, is substantially eliminated during the deformation of the confined billet, and wherein the volume of the die cavity defined by the elements can be selectively controlled.
  • FIG. 1B billet 23 is shown as being confined within variable shape die cavity 22 and pressurized by the action of ram 17 exerting downwardly directed force thereon.
  • the volume defined by die cavity 22 is equal to the volume of billet material 23 contained thereby.
  • the volume of die cavity 22 in order to maintain billet 23 confined and pressurized during the deformation thereof to form cup-shaped article 26, the volume of die cavity 22 must be maintained constant during the variation of its shape from that conforming to the billet 23 (FIG. 18) to that conforming to the cup-shaped article 26 (FIG. 1C).
  • the rate of increase of the volume of the wall portion of the cupshaped member must be equal to the rate of decrease of the volume of the base portion of the cup-shaped article being formed. Since the cross-sectional area of the material in the wall portion is less than that in the base portion by an amount equal to the cross-sectional area of mandrel 19, it becomes evident that in order to maintain the desired constant volume relationship between the die cavity and the billet material, outer die section 12 must be advanced at a faster rate than ram 17. Any particular relationship between the two elements is determinable mathematically by anyone of ordinary skill in the art.
  • outer die section 12 moves through a distance d which is equal to the length of the wall portion of the cupshaped article 26.
  • the movement of the billet material during deformation involves a lateral displacement of material above mandrel 19 out of the path of inner die section on mandrel 19 and into the volume of the die cavity which defines the wall portion of the cup-shaped article being formed.
  • a unit of billet material is displaced around mandrel 19 from a point in the base portion of the material to a point in the wall portion, it ceases to experience any relative movement with respect to outer die section 12 and advances axially therewith at an equal rate along mandrel 19.
  • deformation apparatus In order to realize fully the advantages which the present invention offers, i.e. in order to facilitate the forming of cupshaped articles by a single deformation operation from materials which would be incapable of single operation deformation without fracture under ordinary ductility conditions, deformation apparatus must be provided which is capable of exerting and supporting the pressures necessary for increasing the capability of billet of solid plastic material to be deformed without fracture. in other words, apparatus must be provided for establishing a high-pressure environment in which to conduct the article forming process. The magnitude of the pressures which may be required can become quite high.
  • FIGS. 2-4 show a novel apparatus, designated generally by the reference numeral 40, in accordance with the present invention, which is capable of generating and supporting pressures of such magnitude as are necessary to increase the duetility and facilitate the deformation without fracture of materials which would otherwise fracture under atmospheric ductility conditions.
  • Apparatus 40 includes a machine block 42 which is rigidly secured to a foundation member 43 by suitable means (not shown).
  • Machine block 42 is provided with a bore 45 with extends longitudinally into a portion of machine block 42 from the lower surface thereof as seen in FIG. 2.
  • the outer portion of bore 45, the lower portion as seen in FIG. 2 is provided with a threaded counterbore 49 for securely receiving an end plug 50.
  • Counterbore 49 and bore 45 cooperate to define a shoulder 48 which engages the upper surface 51 of end plug 50 to limit the entry of end plug 50 into machine block 42.
  • main bore 45 extends longitudinally into only a portion of machine block 42.
  • the inner end of bore 45 i.e. the upper end as seen in FIG. 3, defines a transverse surface 52 in which there is formed a longitudinally extending annular channel 54, the purpose of which is discussed below.
  • a bore 55 which communicates with main bore 45 through a mandrel bore 56.
  • Bore 55 accommodates both the base portion 58 of a mandrel 59 which extends into main bore 45 through mandrel bore 56 and a plug 60 which serves as a bearing element between the base portion 58 of mandrel 59 and the surface of foundation member 43.
  • End plug 50 is provided with a longitudinally extending through-bore 61 which is of smaller diameter than main bore 45 and cooperates therewith to form a stepped cylinder for slidably receiving a stepped piston-vessel 63 therein.
  • piston-vessel 63 is a piston in the sense that it responds to exerted fluid pressures to reciprocate the outer die section of the apparatus in the manner discussed in detail above with respect to the apparatus of FIG. 1, and is a vessel in that it provides radial support for the pressures generated during the deformation process.
  • Piston-vessel 63 is a stepped cylindrical member, outer surface of which comprises an upper portion 64, the diameter of which is substantially equal to the diameter of main bore 45, and a lower portion 65, the diameter of which is substantially .equal to the diameter of bore 61 in end plug 50.
  • Connecting the surface of upper portion 64 with the surface of lower portion 65 is a radially extending annular shoulder 66 which cooperates with the upper surface 51 of end plug 50, the surface of main bore 45 and the surface of lower portion 65 of piston-vessel 63 to define an advance fluid chamber 70 (FIG. 4). Extending longitudinally into piston vessel 63 from the lower surface thereof as seen in FIG.
  • first bore 67 the upper end of which is provided with threads 68 for rigidly receiving a lower end cap 69.
  • a threaded second bore 73 Extending longitudinally into piston vessel 63 from the upper surface 71 thereof, is a threaded second bore 73 for rigidly receiving an upper end cap 75.
  • a stopped annular shoulder 77 Disposed between first bore 67 and second bore 73 is a stopped annular shoulder 77, the upper step of which cooperates with upper end cap 75 to define an annular channel 78 and the lower step of which cooperates with lower end cap 69 to define an annular channel 79.
  • the inner surface of shoulder 77 defines one surface of a support fluid chamber for containing fluid for supporting the pressures experienced during workpiece deformation, and the annular channels 78, 79 accommodate fluid pressure seals 81 and 82 relatively, for preventing the leakage of fluid from the fluid chamber.
  • a ram bore 86 Extending longitudinally into lower end cap 69 from the lower surface 84 thereof is a ram bore 86, which communicates with a punch bore 89 extending longitudinally into lower end cap 69 from the upper surface 88 thereof.
  • Ram bore 86 is larger in diameter than punch bore 89 and the inner transversely extending surface connecting the two bores thus defines a shoulder 90, the purpose of which is discussed below.
  • Upper end cap 75 is provided with a longitudinally extending mandrel bore 92 therethrough and an annular shoulder 94 extending upwardly from the upper surface 95 thereof.
  • Annular shoulder 94 is slidably receivable within the annular channel 54 of machine block 42 and cooperates therewith to divide the space in main bore 45 above piston-vessel 63 into a central chamber 97 and an annular outer chamber 98.
  • Also provided in upper end cap 75 are a plurality of fluid passages 101 for communicating central chamber 97 with the lower surface 102 of upper end cap 75 adjacent mandrel bore 92. The radially outer portion of the lower surface 102 of upper end cap 75 is relieved to define an annular shoulder 104, the purpose of which is discussed below.
  • the lower surface 102 of upper end cap 75, the upper surface 88 of lower end cap 69 an the surfaces of shoulder 77 and channels 78 and 79 of piston-vessel 63 all cooperate to define a chamber within which is received a die apparatus designated generally by the reference numeral 108.
  • Die apparatus 108 which as shown in partially cutaway perspective in FIG. 5, comprises a mandrel 59, a punch element 109 and an outer die section designated generally by the reference numeral 110.
  • Punch 109 and outer die section 110 are both axially movable and cooperate with fixed mandrel 59 to define a variable shape die cavity 111.
  • Outer die section 110 is an expandable forming die including a plurality of generally wedge-shaped segments 112 which are positioned for limited radial movement toward and away from the shoulder 77 of piston-vessel 63. The radially inward movement of segments 112 is limited by the surface-to-surface engagement of the radially extending surfaces 114 on each of the segments 112.
  • sealing cylinder 116 which is positioned concentrically of segments 112 when considered collectively.
  • sealing cylinder 116 also cooperates with annular shoulder 77 and seals 81 and 82 in annular channels 78 and 79 to define a support fluid chamber 117 (FIG. 2) for containing pressurized fluid to support the radially directed forces which are generated during the deformation process.
  • each wedge-shaped element 112 Formed on the radially inner axially extending surface of each wedge-shaped element 112 is an upper arcuate surface 124 and a lower arcuate surface 125.
  • Lower arcuate surface 125 is disposed radially outwardly of upper arcuate surface 124 by an amount substantially equal to the desired wall thickness of a cup-shaped article to be formed.
  • mandrel die bore 127 with forming die bore 129 defines a radially extending shoulder 130 which is of a depth substantially equal to the desired wall thickness of a cup-shaped article to be formed. Further, the entire surface of die bore 129 is provided with a shallow spiral thread 131 which renders the surface of die bore 129 a high friction surface of the type discussed above generally with respect to FIG. 1.
  • punch 109 having a base 137, is secured on the upper surface of a ram 139 by a ring 140 and a retaining plate 141.
  • Punch 135 extends coaxially with punch bore 89 and, as is discussed below, is slidably receivable therein.
  • a spring 143 Surrounding punch 109 is a spring 143 which supports a billet retainer plate 144.
  • Formed centrally of plate 144 is a cylindrical journal 145 adapted for slidably receiving punch 109 therethrough and also for retaining a billet 148 therein during the first phase of the operation of the apparatus.
  • the operation of the apparatus 40 is effected by the selective introduction of pressurized fluids to the various chambers of the apparatus.
  • the introduction of such fluids is accomplished through suitable passages formed in the apparatus. More specifically,-formed in machine block 42 is an ejection fluid passage 150 which communicates central chamber 97 with a source line 152 of suitably pressurized ejection fluid, a retraction fluid passage 154 which communicates outer chamber 98 with a source line 155 of suitably pressurized retraction fluid, and a vent passage 158 for venting annular bore 54 above annular shoulder 94.
  • Formed in end plug 50 is an advance fluid passage 160 for communicating advance fluid chamber 70 with a source line 161 of suitably pressurized advance fluid.
  • a support fluid passage 164 which communicates support fluid chamber 117 with a source line 165 of suitably pressurized support fluid.
  • the required magnitudes of the pressures of the various fluids noted above are dictated by the shape of the article being formed and the material being deformed.
  • the pressures required to accomplish the formation of the cup-shaped article from a 98 percent nickel rod billet discussed above were approximately as follows: ejectior. .luid pressurel p.s.i.; retraction fluid pressure 1,100 p.s.i.; advance fluid pressure 1,100 p.s.i.; and support fluid pressure 35,000 p.s.i.
  • Leakage of pressurized fluids from the respective chambers within apparatus 40 is prevented by the provision of seals mounted in suitable channels formed appropriately in the apparatus elements. More specifically, the leakage of retraction fluid from outer chamber 98 is prevented by a seal 170 mounted in a suitable annular channel formed in annular shoulder 94 for sealing engagement with the surface of channel 54, and a seal 171 mounted in a suitable annular channel formed in the upper portion 64 of the outer surface of pistonvessel 63, for sealing engagement with the surface of main bore 45.
  • seal 171 The leakage of advance fluid from advance fluid chamber 70 is prevented by seal 171 described above, a seal 174 mounted in a suitable annular channel formed in the lower portion 65 of piston-vessel 63 for sealing engagement with the surface of through-bore 61 in end plug 50, and a seal 176 mounted in an annular channel formed in the upper outer surface of end plate 50, seal 176 being in sealing engagement with the inner surface of counterbore 49 in machine block 42.
  • support fluid chamber 117 is sealed against leakage by high-pressure seals 81 and 82 mounted in channels 78 and 79, respectively.
  • FIG. 2 shows the apparatus in an open or billet receiving position
  • FIG. 3 shows the apparatus at the commencement of deformation of the billet 148
  • FIG. 4 shows the apparatus at the completion of the deforming process.
  • punch 109 can be seen to be withdrawn from forming die bore 129, punch bore 89 and ram bore 86.
  • spring 143 is fully extended so as to position billet retainer plate partially beyond the end of punch 109.
  • the extension of plate 144 partially beyond the end of punch 109 causes the formation of a billet retainer cup 146 by the cooperation of journal and the upper end surface of punch 109.
  • the first step of the operation is to position a billet 148 within billet retainer cup 146.
  • the support fluid in support fluid chamber 117 is then pressurized by the introduction of fluid pressure through support fluid source line 165 and passage 164 in piston-vessel 63.
  • the pressurization of the support fluid in chamber 117 generates a radially inwardly directed force against sealing cylinder 116, which in turn bears against the outer surfaces of segments 112 causing them to be displaced radially inwardly against the expanding forces exerted by upper and lower spring elements 121 and 122 as discussed above.
  • the inward displacement of segments 112 continues until the radially extending surfaces 114 are engaged and the upper 124 and lower 125 radial surfaces (FIG. 5) of each segment cooperate to define mandrel die bore 127 and forming die bore 129.
  • the magnitude of the pressure exerted by the support fluid in chamber 117 is such as to close the die segments as described above and to prestress the segmented cylinder formed by the closed segments so that the radially outwardly exerted pressures generated against the surfaces 125 of the segments during deformation are insufficient to open the die.
  • ram 139 With expandable outer die section 110 in the closed position, ram 139 is advanced by suitable means (not shown) so as to introduce billet 148 and punch 109 into forming die bore 129 through punch bore 89.
  • billet 148 is retained in billet retainer cup 146 until plate 144 engages shoulder 90 of ram bore 86 and is held thereagainst by spring 143 during the continued advance of ram 139, punch 109 and therewith billet 148.
  • billet 148 Once having cleared billet retainer cup 146, billet 148 is retained in position on punch 109 by punch 89 and forming die bore 129 during the advance of billet 148 into abutment with the end of mandrel 59, i.e. to the position shown in FIG. 3.
  • billet 148 is shown being retained in position by the lower end of mandrel 59, the upper end of punch 109 and the surface of forming die bore 129.
  • the diameter of forming die bore 129 as measured from top to top of the thread 131 is substantially equal to the diameter of billet 148 and also equal to the desired diameter of the finished cup-shaped article.
  • the depth of the threads may be as desired, but it has been found that a thread depth equal to or less than one half of the allowable diameter tolerance of the final article allows a finished article to be formed in one operation without the necessity for further manufacturing steps such as sizing and the like.
  • the upward displacement of expandable outer die section 1 10 and punch 135 is controlled so as to maintain the volume of die cavity 111 constant while varying its shape from that of billet 148 to that of a desired cup-shaped article 149 (FIG. 4).
  • the material of billet 148 can thereby be maintained both confined and pressurized so that the entire deformation process is accomplished with the material being maintained at the desired state of increased ductility.
  • the actual deformation of the billet 148 is accomplished by deforming forces cooperatively exerted by punch 109 and the threaded surface of forming die bore 129 on the billet material.
  • the force exerted by punch 109 is a direct axial force generated through ram 139.
  • the force exerted by the threaded surface of forming die bore 129 is a longitudinally exerted force which is transmitted to the billet material through the engagement of the billet material with the surfaces of thread 131.
  • the billet material is advanced along the surface of mandrel 59 at the same velocity as outer die section 110 is being advanced and, in this manner, slippage between the surface of the material being deformed and the surface of die bore 124 is precluded.
  • Formation of cup-shaped article 149 from billet 148 is continued by the controlled advancement of punch 109 and expandable outer die section until the article 149 is completely formed as desired. At this point, the introduction of advance fluid into advance fluid chamber 70 is terminated, although the pressure in the fluid body is maintained, and the direction of movement of punch 109 is reversed by ram 139 to that punch 109 is withdrawn from forming die bore 129, punch bore 89 and ram bore 86, from the position of sown in FIG. 4 to that shown in FIG. 2.
  • AFter punch 109 has been withdrawn from the body of apparatus 40, the pressure of the advance fluid is relieved and pressure is reexerted on the retraction fluid in outer chamber 98 from retraction fluid source line (FIG. 2) through passage 154.
  • the now pressurized retraction fluid causes the downward displacement of piston-vessel 63 from the position shown in FIG. 4 to that shown in FIG. 2.
  • downward displacement of expandable outer die section 110 with pistonvessel 63 causes the cup-shaped article 149 to be stripped from mandrel 59.
  • a new blank 148 can be positioned within billet retainer cup 146 and the procedure can be repeated.
  • Cup-shaped article 149 is a finished article which requires no further manufacturing operations for completion.
  • the segmented cylinder of outer die section 10 is prestressed by the pressure exerted by the support fluid in chamber 117 to a magnitude sufficient to preclude opening of the segments 112 during deformation, and article 149 is formed with substantially no flash. Further, the sliding movement of the billet material over mandrel 59 during deformation accomplishes a burnishing of the surface of the cup cavity which can obviate the necessity for any further surface finishing operations.
  • the depth of threads 131 can be made to be equal to or less than one half the diameter tolerance of the part being formed thereby ensuring that the formed part, with surface scores from thread 131, is still within tolerance for the finished article.
  • a complete process for manufacturing a cup-shaped article from bar stock and using the forming process of the present invention requires only the steps of cutting the bar stock to proper length, heat treating if it is desired to establish an initial ductility in the billet, and forming as described above. It may be desired to coat one end of the billet with a suitable lubricant, e.g. Indium or the like, to minimize friction between the billet material and the surface mandrel 59. Even with this additional step, however, the present process is simpler and less expensive than machining processes which heretofore have been required. In fact, savings in the range of an order of magnitude have been realized in the manufacture of cup-shaped articles according to the teaching of the present invention rather than by machining as in the prior art.
  • a suitable lubricant e.g. Indium or the like
  • An additional advantage of the process of the present invention is that irregularly shaped articles can be formed which were not heretofore formable by drawing or extrusion and which, if manufactured by machining, would be so expensive as to render their manufacture commercially prohibitive.
  • an article having an elliptical outer cross section and a polygonal inner cross section could be manufactured by apparatus 40 merely by providing a polygonal mandrel 59 and by manufacturing forming die bore 129 of expandable die apparatus 110 to be elliptical rather than circular as shown.
  • the apparatus and process would be the same and an article, having been formed, would be ready for immediate use.
  • tubular articles having bores extending completely therethrough may be manufactured by the process and with.
  • the apparatus of the present invention by merely manufacturing a cup-shaped article in the manner described above and, thereafter, cutting off the base portion in any suitable manner.
  • the advantages of manufacturing such tubular articles having through-bores in this way are that articles having varying inner and outer cross-sectional configurations can be manufactured from billets in a single forming operation coupled with a cutting operation, and the necessity for machining otherwise difficult to form tubular shapes is obviated.
  • Method of forming an article which comprises:
  • a die system including an outer die, a punch, and a mandrel which together define an enclosed die cavity;
  • Method of forming an article of solid plastic material which comprises:
  • a blank of solid plastic material in a die system including an outer die, a punch, and a mandrel which together define an enclosed die cavity;
  • Method of forming an article form a billet of solid plastic material in a die having a variable shape die cavity including the steps of:
  • Method of forming a cup-shaped article from a billet of solid plastic material in a die having an outer die section, a punch and a mandrel which cooperate to define a variable shape die cavity including the steps of:
  • Apparatus for forming an article from a billet of solid plastic material comprising:
  • said outer die means, said punch means and said mandrel means being relatively movable and cooperating to define a variable shape, enclosed die cavity;
  • outer die means comprises an outer die section having a die bore therein, and said die bore is provided with a high friction surface for frictionally engaging said outer surface of said material for applying said frictional force to the outer surface of said increasingly ductile material.
  • said outer die section comprises a plurality of generally wedge-shaped segments each having at least one arcuate surface thereon, said arcuate surfaces cooperating to define said die bore, and said segments being movable radially inwardly to apply said frictional force.
  • Apparatus for forming a cup-shaped article from a billet of solid plastic material including:
  • mandrel means rigidly secured within said machine block and having a portion extending into said main bore, said portion of said mandrel means extending into said main bore being configured in accordance with the desired configuration of the cavity of said cup-shaped article;
  • piston-vessel mounted for reciprocating movement within said main bore of said machine block, said piston-vessel having a bore extending therethrough;
  • forming die means mounted in said piston-vessel for said die bore of said forming die means is a high friction surface.
  • Apparatus as claimed in claim 13 wherein said expandable forming die is mounted within a chamber formed in said piston-vessel, said chamber for receiving pressurized fluid to provide radial support for said expandable forming die.
US802040A 1969-02-25 1969-02-25 Methods of and apparatus for forming an article having a tubular portion Expired - Lifetime US3631706A (en)

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US (1) US3631706A (xx)
JP (1) JPS5016752B1 (xx)
BE (1) BE746353A (xx)
CH (1) CH522456A (xx)
DE (1) DE2008348C3 (xx)
FR (1) FR2032396B1 (xx)
GB (1) GB1300441A (xx)
NL (1) NL7002592A (xx)
SE (1) SE354977B (xx)

Cited By (8)

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Publication number Priority date Publication date Assignee Title
US4222260A (en) * 1978-05-15 1980-09-16 Wsp Industries Corporation Warm forging of connecting rod caps
US4341106A (en) * 1977-04-13 1982-07-27 Gleason Works Apparatus for controlling the movement of a reciprocatory hydraulically driven element of a metal forming machine
US4627665A (en) * 1985-04-04 1986-12-09 Ss Indus. Cold-headed and roll-formed pick type cutter body with carbide insert
US5119663A (en) * 1991-01-11 1992-06-09 Masco Industries, Inc. Method and apparatus for cold extruding universal seal crosspieces
US5297643A (en) * 1990-12-19 1994-03-29 Kennametal Inc. Cold headed center vacuum drill bit
US5894752A (en) * 1996-09-19 1999-04-20 Sanyo Special Steel Co., Ltd. Method and system for warm or hot high-velocity die forging
US20040025560A1 (en) * 2000-04-25 2004-02-12 Yoshihiko Funakoshi Radioactive substance containment vessel, and radioactive substance contaiment vessel producing device and producing method
US20140335992A1 (en) * 2013-05-08 2014-11-13 Schaeffler Technologies Gmbh & Co. Kg Rotary power transfer disconnect device

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DE2747169C2 (de) * 1977-10-20 1984-04-12 Naučno-issledovatel'skij i eksperimental'nyj institut avtomobil'nogo elektrooborudovanija i avtopriborov, Moskva Verfahren und Vorrichtung zum Herstellen von Hohlkörpern durch Fließpressen von Massivkörpern
WO1984002907A1 (en) * 1983-01-21 1984-08-02 Alkaloida Vegyeszeti Gyar New alkyl diamine derivatives
CN112517816B (zh) * 2020-10-16 2022-04-08 中北大学 外纵筋筒形件双向间歇式差速镦粗复合挤压成形方法
CN112590376B (zh) * 2020-12-15 2022-08-16 高安市南卓五金铸造有限公司 一种用于防火电机尺寸数据的冲压印刷设备

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US3108502A (en) * 1959-10-22 1963-10-29 Henry B Chatfield Punch and die assembly
US3286498A (en) * 1964-02-03 1966-11-22 Gen Electric Compressive forming
GB1081896A (en) * 1963-08-20 1967-09-06 Commissariat Energie Atomique Improvements in or relating to the shaping of metals by pressure
US3406555A (en) * 1966-04-05 1968-10-22 Western Electric Co Cold forming of articles

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GB449420A (en) * 1935-03-13 1936-06-26 Stewarts & Lloyds Ltd Improvements relating to the manufacture of hollow metal articles such as tubes
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US3108502A (en) * 1959-10-22 1963-10-29 Henry B Chatfield Punch and die assembly
GB1081896A (en) * 1963-08-20 1967-09-06 Commissariat Energie Atomique Improvements in or relating to the shaping of metals by pressure
US3286498A (en) * 1964-02-03 1966-11-22 Gen Electric Compressive forming
US3406555A (en) * 1966-04-05 1968-10-22 Western Electric Co Cold forming of articles

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4341106A (en) * 1977-04-13 1982-07-27 Gleason Works Apparatus for controlling the movement of a reciprocatory hydraulically driven element of a metal forming machine
US4222260A (en) * 1978-05-15 1980-09-16 Wsp Industries Corporation Warm forging of connecting rod caps
US4627665A (en) * 1985-04-04 1986-12-09 Ss Indus. Cold-headed and roll-formed pick type cutter body with carbide insert
US5297643A (en) * 1990-12-19 1994-03-29 Kennametal Inc. Cold headed center vacuum drill bit
US5452628A (en) * 1990-12-19 1995-09-26 Kennametal Inc. Cold headed center vacuum drill bit
US5119663A (en) * 1991-01-11 1992-06-09 Masco Industries, Inc. Method and apparatus for cold extruding universal seal crosspieces
US5894752A (en) * 1996-09-19 1999-04-20 Sanyo Special Steel Co., Ltd. Method and system for warm or hot high-velocity die forging
US20040025560A1 (en) * 2000-04-25 2004-02-12 Yoshihiko Funakoshi Radioactive substance containment vessel, and radioactive substance contaiment vessel producing device and producing method
US20070089474A1 (en) * 2000-04-25 2007-04-26 Japan Casting & Forging Corporation Radioactive substance container, manufacturing apparatus thereof and manufacturing method thereof
US20080209972A1 (en) * 2000-04-25 2008-09-04 Mitsubishi Heavy Industries Ltd. Radioactive substance container, manufacturing apparatus thereof and manufacturing method thereof
US7462853B2 (en) 2000-04-25 2008-12-09 Mitsubishi Heavy Industries, Ltd. Radioactive substance containment vessel, and radioactive substance containment vessel producing device and producing method
US7485884B2 (en) * 2000-04-25 2009-02-03 Mitsubishi Heavy Industries Ltd. Radioactive substance container, manufacturing apparatus thereof and manufacturing method thereof
US8661867B2 (en) 2000-04-25 2014-03-04 Mitsubishi Heavy Industries, Ltd. Radioactive substance container, manufacturing apparatus thereof and manufacturing method thereof
US20140335992A1 (en) * 2013-05-08 2014-11-13 Schaeffler Technologies Gmbh & Co. Kg Rotary power transfer disconnect device

Also Published As

Publication number Publication date
DE2008348B2 (de) 1974-06-20
CH522456A (de) 1972-06-30
DE2008348A1 (de) 1970-09-10
DE2008348C3 (de) 1975-01-30
JPS5016752B1 (xx) 1975-06-16
FR2032396B1 (xx) 1974-07-12
NL7002592A (xx) 1970-08-27
GB1300441A (en) 1972-12-20
SE354977B (xx) 1973-04-02
FR2032396A1 (xx) 1970-11-27
BE746353A (fr) 1970-07-31

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