US2804790A

US2804790A - Method and apparatus for forging

Info

Publication number: US2804790A
Application number: US434413A
Authority: US
Inventors: Maurice P Lefere
Original assignee: Lefere Forge & Machine Co
Current assignee: Lefere Forge & Machine Co
Priority date: 1954-06-04
Filing date: 1954-06-04
Publication date: 1957-09-03
Anticipated expiration: 1974-09-03

Description

p 1957 M. P. LEFERE METHOD AND APPARATUS FOR FORGING Filed June 4, 1954 m TE mm my a, P l m m a r 4 ATTORNEY United States Patent METHOD AND APPARATUS FOR FORGING Maurice P. Lefere, Jackson, Mich., assignor to Lefere Forge & Machine Co., Jackson, Mich, a corporation of Michigan Application June 4, 1954, Serial No. 434,413

1 Claim. (Cl. 78-=-9) The present invention relates to improvements in method and apparatus of forging steel billets.

While there are many ways by which the billet work blank may be provided for the initial forging operation, the most inexpensive method is to shear the blank from the bar stock as received from the mill. However, shearing has the disadvantage of distorting the blank and necessitating a preliminary forging operation to square and upset the blank to its full diameter. This preliminary operation is carried throughout with the blank held in the operators tongs to support the blank erect and requires skilled operators to avoid excessive scrap and tool breakage.

Should it be attempted to eliminate the aforesaid preliminary forging operation of squaring and upsetting employing dies of the construction heretofore used, the billet blank being submerged in the bottom die affords the operator no opportunity to hold the blank erect and it may fall to the outer side of the die due to the shearing distortion. When this happens, the punch will provide a forging of unequal walls, concentricity is not obtained and excessive punch breakage will result from glancing blows and the unequal pressure exerted upon the punch by the unequal walls.

According to the present invention I have been able to eliminate the preliminary squaring and upsetting and to this end I have combined a multiple of operations into one continuous operation. Thus I am able to locate, descale, center, and punch the billet blank all in one cycle of operation. The method and apparatus for carrying out the present invention is such that the billet blanks in their distorted sheared condition are taken from the heat and directly inserted into the impression forging die with no preliminary steps being carried out with the blank held in the operators tongs. This permits the employment of less skillful operators and avoids the cost of the preliminary squaring and upsetting operation.

Thus it is an object of the invention to provide a forging method and apparatus, in which the locating and centering of the sheared billets, the removal of scale and the initial shaping of billets is capable of being effected in a single cycle of operations without the necessity of an operator holding onto the billets during one or more preliminary operations.

Another object is to provide a forging die having an improved combined locator and stripper.

A further object of the invention is to provide an improved construction of forging die which enables a billet to be held centered for forging in position where there is efiicient dissipation of heat from the die and which positively ejects the forged billet to position for easy removal at the termination of the forging operation.

The above, and further objects and advantages of the invention, residing in the construction, arrangement and combination of parts and the improved forging operation will appear clear from consideration of the following detail description with reference to the accompanying drawings and from the appended claims.

2,804,790 Patented Sept 3, 1957 In the drawings:

Figure 1 is a vertical section of the lower die of a forging press constructed to operate in accordance with the invention, and showing a sheared billet in its first position of operation,

Figure 2 is a vertical section with the top die in position at the commencement of the forging operation and the bottom die still positioned as in Figure 1,

Figure 3 is a view similar to Figure 2, but showing the operation in its lowered position, and

Figure 4 is a vertical section of the bottom die, with the top die elevated out of the way and showing the finished forging left resting upon the spring actuated stripper and locating plate at the top of the bottom die.

Referring to the drawings, 10 indicates a hollow cup shape casing part of the bottom die, which casing part p is adapted to be supported in the bottom die set (not shown) of a forging press and supports the plate structure carrying the die punch 16.

The die punch is shaped to conform with the article to be forged. The punch 16 is shown fitted upon a base plate 20 by the screw studs 22. A central axial opening 18 permits a tool to be inserted for ejection of the punch 16 from the plate 20. The plate 14 serves as a spacer plate and is interchangeable with other plates. This assembly permits the die punch 16 to be interchanged, depending upon the particular article to be forged, which, in the specific example illustrated, is a shell casing.

Secured to the bottom die casing 10 there is an upper casing part 26, which is telescoped at its lower end into the casing part It? and is secured to the latter by the removable screw studs 28, with the bottom flange 30 hearing against the punch plate 14. An annular well 32 serves to receive the lower end of a coil spring 34 as well as for the collection of the scale and liquid encountered in the forging operation.

At its upper end the casing part 26 of the bottom die is formed or fitted with a flange ring 36, shown secured in position by the screw-studs 38, and projecting inwardly to form an upper limit stop for a combination billet locator and litter plate 40, this plate being normally elevated against said stop by the action of the spring 34.

The plate 4t? has a central opening 42 through which a billet 44 is capable of being introduced, as will be described later.

The top die structure is seen in Figs. 2 and 3 and comprises a hollow body part 46 mounted for reciprocation upon the press and carrying a top closure cap 48 and a removable bottom ring plate 50, which plate serves to hold the upper female die 52 upon the body part 46, as by the removable screw-bolt studs 54. The cap 48 is adapted to be secured in the top die set (not shown) of the forging press.

The upper female die 52 is interchangeable with other dies having a radial shoulder 55 with which the ring plate 51) engages to hold the die upon the casing 46 by the engagement of the screw studs 54 in the bottom of this casing.

Mounted within the top die casing 46 there is a plunger 56 having a bottom plug portion 56' which has a sliding fit through a central opening 58 in the upper die 52 and which plunger has a radial flange 60 and an upper spindle portion 56". A coil spring 62 normally urges this plunger downwardly against the ring 66 which acts as a retainer stop, as seen in Fig. 2, and there is clearance 64 (Fig. 2) between the upper end of the spindle 56" and the cap 48. In the example illustrated the plunger flange 60 engages the top die 52 through the medium of a separate ring 66, which ring serves as a spacer ring and is interchangeable with other such rings. The flange 60 has circumferentially spaced openings 68 through which liquid employed in the forging operation and introduced through ports 70 in the upper die structure can flow to the billet 44 and be deposited in the well 32. The bottom die also has water nozzle openings'72 and a wash out opening 74.

In operation, with the top die elevated to inoperative position and the plate 40 of the bottom die in its elevated position, as seen in Fig. 1, asheared billet 44 is located Within the plate opening 42 so that its sheared end rests upon the top of the die punch 16 and so that its major portion is exposed to atmosphere, whereby to provide for dissipationof heat and prevent undue heating of the die punch 16 and the plate 40.

In the position of Fig. l, the location of the horizontal plane or the plate 40 relative to the tip of the punch 16 is important as the billet 44, when located in the opening 42 and resting on the punch 16, should be held sutlic'iently erect under all conditions of mill tolerances and shearing distortion as to be received within and centered by the walls of the upper female die 52. This is accomplished by regulating the size of the hole 42 and the distance between the tip of the punch 16 and the opening 42. With the billet 44 thus located the top female die is now lowered to engage the plate 40, as seen in Fig. 2. It will be seen from reference to this figure that the female die 52 presents an interior cavity 76 to the upwardly projecting billet and that this cavity is so formed that only the upper end edge of the billet contacts the cavity and a substantial clearance space is formed around the projecting billet portion. The billet is formed to shape in this space, with attendant discharge of scale through the space 78 (Fig. 3) formed between the plate opening 42 and the upper end of the die punch 16. The forging operation is completed by lowering the top die, the effect of which is to depress the plate 40 against the action of the spring 34 and cause the billet to be forced around the die punch 16 and to forge the billet into the shape of the space defined between the upper end of the die punch 16 and the cavity 76. The upper end of this cavity is closed by the lower end of the plug 56, which plug, together with the plunger 56 and its upper spindle part 567, is pushed upwards, as seen in Fig. 3, against the action of the spring 62, until the upper end of the spindle part 56" contacts the cap 48. In this position the plunger flange 60 will be spaced upwardly from the upper end of the spacer ring 66 and the completed forging 80 will be supported at its lower end'upon the plate 40.

With the parts positioned as seen in Fig. 3, the top die structure is now moved upwards and will be closely followed by the plate 40 which continues to maintain contact with the bottom end of the forging 89 due to the action of the spring 34, while at the same time as the lower end of the plunger portion 56' maintains contact with the upper end of the forged billet. The plate 40, therefore, now functions to lift the forging 80 until the plate is brought to rest against the stop ring 36. When this occurs, continued upward movement of the top die structure will be attendant with lifting of the plunger 56 from the position seen in Fig. 3 and re-positioning there of to its originalposition as seen in Fig. 2, when the top dierstructure is brought to, rest in its elevated position. In this position, the forging 80 is left seated upon the plate 40, from which it can be readily removed, as will be appreciated.

It will be noted from Fig. 2 that directly about the,

plate 40, there is an annulus of clearance between the billet 44 and the walls of the cavity 76 of the female die 52. This clearance provides freedom of radial flow for the material of the billet as it is being forged pending the lowering of the plate 40 to below the tip of the punch 16 whereby forging of the billet takes place above the plate 40 and disposes the billet outside the opening 42 so as the plate 40 can function as a stripper.

It will be realised, therefore, that the invention provides for the locating of a sheared billet in position for forging, forging the billet to shape, with free disposal of scale, and positive ejection of the formed forgings in a continuous cycle of operations without the necessity of an operator handling the billet after the same has been positioned within the plate opening 42 to rest upon the top of the die punch 16.

As above stated, the bottom die punch is readily removable and interchangeable with other die punches. The top die is also readily removable and interchangeable, as by removing the screw-bolt studs 54 and ring plate 50.

, Having thus disclosed by invention, what I claim as novel and wish to secure by Letters Patent is as follows: A device for forging metal billets, comprising in combination a fixed, upwardly extending punch, a female die vertically reciprocable coaxially of said punch and terminating downwardly in an open end, a horizontal plate mounted for vertical reciprocation, stop means preventing upward movement of said plate beyond an uppermost position, and means biasing said plate toward said uppermost position, said plate having a hole therethrough coaxial with said punch, said plate in its said uppermost position as determined by said stop means being so disposed above the top of said punch that the marginal edges of said hole are adapted to encircle a said billet intermediate the ends thereof while it is resting on the upper end of said punch, said marginal edges in said uppermost position and said female die providing the sole lateral support of said billet, and said open end of said die being adapted to contact the upper surface of said plate outwardly of said marginal edges, said structure being such that the bottom of a said billet in said hole resting on said punch will be initially laterally supported solely by said marginal edges, and said open end of said die upon a downstroke will support the upper end of said billet and will contact said plate and force said plate below the lower end of said billet, and said die and punch will thereafter coact to pierce said billet and expand the outer diameter of said billet to a diameter greater than the diameter of said hole, and upon the next upstroke of said die said biasing means will force said plate upward until the upper surface of said plate adjacent said marginal edges contacts the expanded lower end r of said billet and strips said billet from said punch.

References Cited in the file of this patent UNITED STATES PATENTS 929,628 Pilcher July 27, 1909 2,314,148 Lefere Mar. 16, 1943 2,326,606 Biggert Aug. 10, 1943 2,411,379 Langhammer Nov. 19, 1946