US2168641A - Die mechanism - Google Patents

Description

8, 1939.. AAAAAAA OG AST 2,168,641

DIE MECHANISII Filed March '7, 1938 Patented Aug. 8, 1939 UNITED SKATES PATENT OFFICE DIE MECHANISM Ind., a corporation Application March 7, 1938, Serial No. 194,251

13 Claims.

This invention relates to an apparatus for forming metallic articles and particularly to an apparatus for increasing the'thickness of the section of a metallic member. It has for another purpose to provide a means for increasing the thickness of a section and changing the shape of a metallic member by pressure. Other objects will appear from time to time in the specification and claims.

The invention is illustrated more or less diagrammatically in the accompanying drawings,

wherein:

Figure 1 is a plan view of one part of a die for carrying out the present invention with parts of the die and the product shown in section before the operation has been carried out;

Figure 2 is a generally similar view after the forming operation has been carried out;

Figure 3 is a section showing an adaptor which is formed by the apparatus of Figures 1 and 2 and subsequent machining;

Figure 4 is an elevation showing a modified form of adaptor having ribs made by the apparatus of the present invention;

5 Figure 5 is a sectional view generally similar to Figure 3, illustrating a further modified form of connector;

Figure 6 is a transverse sectional view taken. at line 6-6 of Figure 4 illustrating the part of Figure 4 after the forming operation is complete and while it remains in the die;

Figure 7 is a sectional View illustrating a modified form of die construction in which the die is not split. The figure indicates the relative position of the parts at or near the commencement of the forming step;

Figure 8 is a section similar to Figure '7 showing the position of the parts after the completion of the forming step;

Figure 9 is a transverse section; taken at line 99 of Figure 7 Figure 10 illustrates a further modified form. of die construction in which a split die arrangement is used.

Like parts are designated by like characters throughout the specification and drawings.

The numeral I is one of the die members. In Figures 1 and 2 it is shown in plan. There will ordinarily be two such die members and they may be of identical shape. 2-2 are guiding and positioning parts engaged by both of the die members which serve to keep the proper alignment of the parts.

The shape of the die depends of course, upon the product that is to be made. For the prodnot illustrated herewith each die has two generally semi-cylindrical cavities 3 which may be reduced as at 4. When the two die members I, I are put together they form a cylindrical cavity 3, and 4 having two main diameters and connected 5 by the shoulder 5.

In the particular form illustrated herewith a tube 6, which has a reduced portion 1 is inserted in the die cavity and the die 8 having a shoulder 9 and a reduced portion I0 is inserted in the open 10 end I of the tube. The reduced portion Ill is preferably shouldered as at I I and this shoulder is brought into contact with the open end of the reduced portion I of the tube. The portion II) may have a perforation or depression I2 formed in it. 15

A second die member I3, having a shoulder I4 and a passage or conduit I5, is then inserted in the open end of the die member I. The outer diameter of the die I3 is greater than the inner diameter of the portion 6 and hence abuts against its end and does not penetrate it.

At a suitable state in the process used, the interior of the tube '6, 'I is filled with a body of material I6. This material may be of any desired nature. For one purpose soft metal may be used. Any material which will sufficiently resist compression but is also sufficiently free for deformation may be used.

When the parts are all in the position of Figure 1 and both of the dies I, I are in place the two 30 die members 8 and I3 are further advanced to collapse the tube on itself and to force its two ends together toward each other. The tube being filled with the metal I6 cannot be collapsed lat erally and hence the material of the tube fiows 35 and the tube is shortened'to the form of Figure 2 and its walls thickened. As this takes place the material I6 is discharged or extruded through the passage I5 in the die I3 and may emerge as a wire or rod IT. The size of the passage I 5 is made such that the material IE is discharged through it sufficiently rapidly to permit the dies 8 and I3 to move inwardly from the position of Figure l to that of Figure 2, but it is discharged sufficiently slowly to prevent collapsing of the tube 6, l and thus the material of the tube is constrained to flow longitudinally in the main, so that the'walls of the tube as they are shortened are correspondingly thickened. Thus the tube at the completion of the movement of the dies, as shown in *50 Figure 2 comprises a narrower portion I8,'which may be somewhat shorter than the original narrow portion 1, and a thickened and shorter portion I9 which is correspondingly much shorter and much thicker than the original wider portion 6. During the same operation an annular ledge or projection 20, may be formed within the tube. Whether or not it is formed, depends upon the shape and amount of travel of the die members 8 and [3.

The form shown in Figure 4 differs from that of Figure 3 by the fact that there are ribs 2| formed on the larger portion l9 and by the further fact that an enlarged lip or flange 22 is formed on the outer end of the portion I9.

Dies suitable for makingthe form of Figure 4 are illustrated in Figure 6 and they comprise two dies 23, 23 generally similar to the dies l, I having each a semicylindrical cavity 24 shaped as at 25 to produce the ribs 2|.

The member shown in Figure 5 is substantially the same as that of Figure 3 except that the inner annular shoulder 20 is not present and the device is threaded exteriorly.

In the modified form, as shown in Figures '7 and 8, a solid die 26 is used. As shown, it is provided with a hollow or chamber portion 27 within which is movably mounted a forming member 28, which is preferably reduced at its inner end as at 29. A shoulder 30 is pro-vided at the inner end of the reduced portion 29 and the member 28 is provided with a passage 30a extending from its inner end to a point outside of the member 26. The die member 28 may have an enlarged guide portion 3! which preferably is formed integrally with it, but might be otherwise formed, and which contacts the interior of the chamber 21. The member 32 is secured to or in contact with the die member 28, and when desired, may be used to force the die member inwardly by hydraulic or any other desired power means.

The forming portion of the die 26 comprises a generally cylindrical cavity 33 which is preferably of somewhat larger size than that which it is desired to give to the exterior of the finished piece which is formed in it. It may be provided, if desired, with an annular portion 34 from which one or more longitudinally aligned grooves 35 extend toward the inner end of the chamber or bore 33. The relationship of these grooves to the total bore is indicated particularly in Figure 9. The bore 33 is reduced as at 36 to the diameter of the unreduced portion of the die member 28. 31 is a third die member. It is shaped to fit the larger diameter of the bore or cavity 33. It may be provided with a stop or shoulder 38, and a portion 39 against which pressure is exerted by any desired mechanism. As shown in Figures 7 and 8, the construction of those figures may be supported upon a base 40 and the die is indicated as being in an upright position. This is not essential and it might be in any other convenient position.

In the forms shown in Figure 10, a split die is used, of which only one portion is shown. That portion is indicated at 4| and comprises a member having a semi-cylindrical cavity 42 formed in it. This cavity has the shape which it is desired to give to the exterior of the finished article to be formed. It may have an annular groove 43 from which extend toward the inner end of the die cavity one or more axially aligned'grooves 44. In the particular form here shown, the cavity 42 is reduced or necked downwardly as at 45. Guiding pins 46 may be used. It is to be understood that the other half of the die is the same as that shown and that the two are brought and held together when a forming operation is to be carried out, so that the work piece is held in proper position throughout the working operation.

A further forming member 41 is positioned in the reduced end of the cavity 45 and is provided with a reduced portion 48 which is smaller than the diameter of the reduced portion 45 of the space or cavity 42, and thus an annular clearance remains when the reduced portion 48 is in the position shown in Figure 10. The member 41, 48 is provided with a passage or perforation 49 which extends from its interior and therefore from the interior of the die assembly to the exterior.

The moving member of the die assembly of Figure 10 comprises a plunger 59 which is of the same size as the major diameter of the cavity 42 and fits snugly within it. It may be provided with a stop or shoulder 5| and with the portion 52, against which pressure is exerted by any desired means.

In all of the forms illustrated in Figures 7, 8, 9 and 10, a body of supporting material 53 is positioned within the work piece 54, which is to be shaped in the forming operation. It will be noticed that in Figures 7 and 10, which show the dies at or approximately at the commencement of forming, that the work piece comprises a tubular member which is initially reduced or necked inwardly as at 55. When pressure has been exerted in either of the die forms, the member which is shown in detail in Figure 4 is formed. Thus the die mechanisms of Figures 7 to 10, inclusive, show modified forms for producing parts of the type generally indicated in Figures 3, 4 and 5, although die assemblies of the type indicated may be used to produce a wide variety of other forms, whether tubular or not, and whether open-ended or not. Thus, parts which are open only at one end or at one point may be formed by dies of the type generally indicated in the accompanying drawings.

The supporting material used in the forms of Figures '7 to 10, inclusive, is preferably the same as the material shown in the earlier figures, and when the forming operation is complete, a portion of this supporting material 53 will have been forced or extruded out through the passage 30a or the passage 49, and may extend therefrom in the form of a wire or rod 56.

In the form illustrated in Figures 7, 8 and 10, the penetrating die member 29 projects inwardly into the enclosing die member to a point beyond the reduced portion, that is to say, to a point beyond the shoulder. The efiect of this is to prevent the formation of an annular ledge or projection as the member 20 shown in the earlier figures. When the member 29 or the member 48 projects inwardly this far, a certain amount of the supporting material 53 will not merely contact the inner end of the member 29 but will surround a portion of its exterior and lie between it and the inner face of the tube 54, 55. When this arrangement is used, no ledge or member 20 will be formed. It is to be understood that the member In of the earlier figures might be lengthened so that it projects inwardly beyond the inner end of the reduced portion 1 of the tube 6.

A further difference between Figures 1-6 inlusive and that shown in the later figures is that in the later figures the passage in the die through which the supporting material escapes is preferably provided with two diameters, the

smaller diameter serving as a control orifice and of the supporting material is possible. The pas sage l in the die member l3 might be similarly arranged so that there would be formed in that die a control orifice and a discharge passage.

In both forms of the die mechanism that portion of the die which penetrates within the tube serves as a support for it and wholly or largely prevents its change in shape where supported. While the invention is illustrated in connection with the formation of tubular members which'are open at, at least, two points it could be utilized in connection with the formation of a member open at more than two points or open at only one point, and the relative shape or proportion of the die member which penetrates within the part that is to be formed or whose shape is to be changed, may be very largely varied. For example, the die member Ill, 29 or 48 might penetrate much farther into the tube or other member which is being treated and might contact its inner wall, as shown, for a greater or less distance depending, among other things, upon the shape which the member originally has before final formation and also upon the shape which it is to have finally.

The use and operation of. the invention are as follows:

To carry out the invention, dies are prepared of proper shape and. size to give to the article to be manufactured its desired shape. The particular shape shown is an adaptor and in the form shown it may be made of copper. One end is relatively thin and may be readily joined to another copper or similar member.

The other portion is thickened to receive a thread which may be internal or external and thus may be readily secured to a member of any material by means of corresponding threads formed on the member to which it is joined. The particular tubular member 6, i which is here shown as being formed into the adaptor, may be initially made as shown with a reduced neck-like portion, or may originally be made of a tube having a uniform diameter, a portion of which is subsequently reduced to produce the neck.

Assuming that the dies are prepared, a member such as the tube 6, l which may be made by drawing, electrolytically or in any other manner, is put into the dies 2, 2. Suitable material It is put inside the member which is to be shaped. This material may be metal or any other material which is of such nature that it will support the tube during the forming operation without permitting undesired distortion of the tube, such as collapsing, folding, and the like, and at the same time it must be sufficiently ductile to be able to escape through the passage l5 readily enough to permit the desired inward movement of one or both of. the dies 8, I3. The size of the passage I5 is proportioned to the nature of the material 16, to the travel which is to be given the dies and to the shape which it is desired to give finally to the piece which is being worked upon, and the nature of the material [6 and the size of the passage l5 are thus related to each other and the result must be such that the material l6 escapes suficiently rapidly from Within the tube 6, I to permit proper reforming of the latter and to permit proper movement of the movable die members and at the same time sufiiciently slowly to furnish adequate support to the tubular member and to prevent undesired distortion of the latter. The material I6 is thus for all practical purposes preferably non-compressible, and at the completion of the operation,

as for example as shown in Figure 2, a large proportion of the material l6 has been extruded through'the passage [5 from which it may shape of die or of. article to be finally manufactured. The so-called die or mold within which the tubular or hollow member is positioned may be made in any desired manner of one part or more than one part. As shown, it is indicated as made of two parts clamped together, but this arrangement may be altered.

In carrying out the method of the present invention, the entire tubular portion may be thickened. As shown, however, the portion 1 is not thickened. It is merely compressed and given agreater density of structure, but if desired, this portion might be compressed and thickened just as the portion 6 is thickened and compressed into the portion l9. During the forming operation carried out in the present invention, the crystalsof the metal reorient themselves into a more homogeneous mass and the strength and general physical properties of the article are very much increased because of the pressure exerted upon them during the forming operation. The material l6, which is ordinarily soft metal, is under pressure and prevents the tube from wrinkling or buckling, and at the same time exerts pressure on the interior of the tube 6, 1, so that the entire body of the tube is subjected to great pressure during the forming operation which, as above noted, not merely reforms the tube but causes a rearrangement of the particles of the metal of which it is formed, which results in a great improvement of the physical properties of the metal. Obviously, machining operations, such as threading, may be readily carried out and the dies may, if desired, be so shaped as to produce ribs, ears and the like, as shown in Figures 4 and 6.

The forms of the devices shown in Figures '1 to 10, inclusive, are approximately the same as those described in the earlier figures, except for the following differences. The member which is to be formed is preferably smaller or of less diameter than the die cavity. This has many advantages, among them being that an unsplit die may be used to form a member such as that shown in Figure 4 with a raised flange 22 and raised members 2|. Because the major diameter of the die cavity is larger than the tube, it may be sufficiently large to include in its radius cavities for the enlargements 2| and 22, and thence, when forming is complete, the member may be discharged or withdrawn from the die without the necessity of. opening it. This permits the use of a closed die instead of a split die.

With the parts as shown in Figure 7, pressure is exerted onthe member 31 and it forced inwardly to the final position shown in Figure 8. Initially, the pressure on the end of the tube or work piece 54 and on the supporting material 53 causes the supporting material to expand laterally until it has enlarged the diameter of the tube and brought it in contact with the interior surface of the cavity 33. As the pressure continues, and the member 31 is forced inwardly, it

continues to exert pressure on the end of the tube and on the supporting material, and thus the tube is collapsed endwise, and since it is sup-. :orted from within andcannot' be distorted or buckled inwardly, the metal is consolidated and the thickened member, such as that shown in Figure 8 and Figures 3, 4 and 5, is produced. The reduced neck portion 55 of the tube is not appreciably changed since it is supported from the start between the inner walls of the reduced portion 36 of the cavity and the reduced portion 29 of the die member 28 and is therefore rigidly held to size and is not altered as to shape.

After the parts have been moved to the position shown in Figure 8, the work piece has been formed and is ready for removal. This is done by withdrawing the member 31 and then forcing the die member 28 inwardly, for example, by exerting pressure upon the member 32, and thus the work piece with some of the supporting material is forced outwardly from the die and ejected. It may be then removed and that portion of the supporting material which remains in the die is subjected to whatever degree of heat is necessary to cause it to flow out of or to be readily removed from the interior of the fitting.

The operation of the form shown in Figure 10 is generally the same as that just described, since the work piece 54 is smaller than the major diameter of the member 42, but since it is a split die assembly, when the part has been completely formed, the die is opened and the work piece is removed.

While the die mechanisms of Figures '7 to 10,-

inclusive, have been shown with cavities 34 and 35 and 43 and 44 to produce enlargements 2| and 22, either of these types of die mechanisms may be used to produce the simple member shown in Figure 3 without any exterior enlargements.

While as a matter of convenience, the passage for the discharge of supporting material from within the work piece is shown in Figures '7 to 10, inclusive, as being formed in that member of the die assembly which is stationary during operation, it might be formed in the other member, or, if desired, a passage might be formed in both members. The size of the passage or passages for the escape of supporting material is in any event proportioned to the size of the parts to the pressures used, to the speed of operation, and to the other factors controlling the conditions of the operation of the parts. In general, the escape passage or passages must be of such size as to permit the supporting material to be extruded or to be discharged sufliciently rapidly to permit proper operation of the die mechanism at the desired speed, but slowly enough to make certain that the work piece issufiiciently supported from within by the supporting material to prevent buckling, distortion or other unsatisfactory results.

I claim:

1. In combination in a metal forming apparatus, means defining a cavity, a die member extending into said cavity, and means for moving said die inwardly, said die member shaped to fit snugly within said cavity, said die member provided with an open ended passage formed in it extending from a point inside said cavity to a point outside said cavity, and having an open end outside of said cavity.

2. In combination in a metal forming apparatus, means defining a cavity, a plurality of die members extending into said cavity, and means for moving them inwardly, one of said die members shaped to fit snugly within said cavity, one of said die members provided with an open ended passage formed in it extending from a point inside said cavity to a point outside said cavity, and having an open end outside of said cavity.

3. In combination in a metal forming apparatus, means defining a cavity, a plurality of die members extending into said cavity, and means for moving them inwardly, one of said die members shaped to fit snugly within said cavity, the other provided with a portion fitting within said cavity snugly and with a portion positioned within but out of contact with the walls of said cavity, one of said die members provided with an open ended passage formed in it extending from a point inside said cavity to a point outside said cavity, and having an open end outside of said cavity.

4. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, and a die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity, and means for the discharge of material from the interior of said cavity to the outside, said means comprising a passage extending from within said cavity to a point exterior thereto, said passage shaped adjacent its inner end with a control orifice.

5. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, and a die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity, said die member being provided with a passage extending from within said cavity to a point exterior thereto, said passage shaped adjacent its inner end with a control orifice and being enlarged at a point outwardly with respect to said control orifice.

6. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, said cavity having the final shape of the article to be formed, and a die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity, said die member being provided with a passage extending from within said cavity to a point exterior thereto, said passage shaped adjacent its inner end with a control orifice and being enlarged at a point outwardly with respect to said control orifice.

'7. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, a die member positioned partly within said cavity and contacting said cavity through only a portion of the length of said die member, and a die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity, one of said die members being provided with a clear, open ended passage extending from within said cavity to an open ended point exterior thereto, for the discharge of material from said cavity.

8. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, a die member positioned partly within said cavity and contacting said cavity through only a portion of the length of said die member and spaced away from said cavity throughout a portion of its length, and a second die member shaped to fit snugly within said cavity and means for moving it inwardly Within said cavity, one of said die members being provided with a passage extending from within said cavity to a point exterior thereto.

9. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, a die member positioned partly within said cavity and contacting said cavity through only a portion of the length of said die member and spaced away from said cavity a distance equal to the wall thickness of the member to be shaped throughout a portion of its length, and a second die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity, one of said die members being provided with a discharge passage extending from within said cavity to a point exterior thereto.

10. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, a die member positioned partly within said cavity and contacting said cavity through only a portion of the length of said die member and spaced away from said cavity a distance equal to the wall thickness of the member to be shaped throughout a portion of its length, and a second die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity, one of said die members being provided with an open ended discharge passage extending from within said cavity to a point exterior thereto, said passage shaped adjacent its inner end with a control orifice.

11. In combination in a metal forming apparatus adapted for the cold formation of metal parts, means defining a cavity, a die member positioned partly within said cavity and contacting said cavity through only a portion of the length of said die member and spaced away from said cavity a distance equal to the wall thickness of the member to be shaped throughout a portion of its length, and a second die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity, one of said die members being provided with a passage extending from within said passage to a point exterior thereto, said passage shaped adjacent its inner end with a control orifice and being enlarged at a point outwardly with respect to said control orifice.

12. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, a die member positioned partly within said cavity and contacting said cavity through only a portion of the length of said die member and spaced away from said cavity a distance equal to the wall thickness of the member to be shaped throughout a portion of its length, and a second die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity toward said first mentioned die member, one of said die members being provided with a passage extending from within said passage to a point exterior thereto, said passage shaped adjacent its inner end with a control orifice and being enlarged at a point outwardly with respect to said control orifice.

13. In combination in a metal forming apparatus, adapted for the cold formation of metal parts, means defining a cavity, said cavity having the final shape of the article to be formed, a die member positioned partly within said cavity and contacting said cavity through only a portion of the length of said die member and spaced away from said cavity a distance equal to the wall thickness of the member to be shaped throughout a portion of its length, and a second die member shaped to fit snugly within said cavity and means for moving it inwardly within said cavity toward said first mentioned die member,

one of said die members being provided with a passage extending from within said passage to a point exterior thereto, said passage shaped adjacent its inner end with a control orifice and being enlarged at a point outwardly with respect to said control orifice.

ALFRED C. ARLBOGAST.

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