US3046653A - Forging of rings and similar parts - Google Patents

Description

Filed May 14, 1958 3,046,653 FORGING F RINGS AND SIMILAR PARTS Josef Martinek, Brno, Czechoslovakia, assignor to Zavody presneho strojirenstvi Lisen narodni podnik zavod Antonina Zapotockeho, Lisen, Czechoslovakia Filed May 14, 1958, Ser. No. 735,149 4 Qlaims. (Cl. 29-552) This invention relates to methods of and machines for forging rings and similar parts, for example, anti-friction bearing rings.

It is common practice to use as a starting material bars heated to the upsetting temperature. The end of the bar is forged in upsetting dies of the required shape. This operation is usually performed in two stages in the same forging machine using two upsetting tools which are located either above one another or side by side.

In the first stage, the heated end of the bar is preforged so that a shoulder is formed, the diameter of which corresponds to the required diameter of the ring. Simultaneously, a part of the bore of the ring is pre-forged. During the second stage, an upsetting mandrel completes the shaping of the bore and at the same time separates the rings from the bar. In some cases this separation is carried out as a separate operation in a third stage.

With the known method, forging requires at least two working strokes of the machine. During this operation, the forge bar must be shifted from one tool to the other and the tools must therefore be divided and must open simultaneously with the clamping device which clamps the bar while it is being upset. As a result of this shifting of the bar, its heated end quickly cools off and it must be frequently re-heated. The mechanism of the forging machine is complicated and its operation calls for heavy work by two men. Failures often occur.

One object of the present invention is to provide a method of forging rings in which the pre-forming and finishing of the rings are carried out during one stage only and during a single working stroke of the ram.

According to the present invention .a method of forging metal rings or like parts comprises the steps of heating one end of a bar to an upsetting temperature, clamping the bar, upsetting the heated end of the bar within a die by the advance of a mandrel, forming a bore within the upset portion of the bar by the continued advance of the mandrel, unclamp ing the bar, separating the upset portion of the bar from the remainder of the bar by the continued movement of the mandrel and simultaneously upsetting the said separated portion within the die by the advance of an upsetting bushing to form said portion to its final shape.

For a better understanding of these and other features of the invention there will now be described by way of example only anembodiment thereof with reference to the accompanying drawings in which:

FIGURE 1 is a diagrammatic plan, partly in section, of a forging machine for performing the method of the invention;

FIGURE 2 is an elevation of a cam for controlling the clamping of the bar to be upset;

FIGURE 3 is a detailed view illustrating part of the mechanism for feeding the bar, and FIGURE 4 shows an alternative mechanism for actuating the clamping device.

In FIGURE 1, the parts of a forging machine are shown in the position in which they arrive at the end of the working stroke of a ram 5 which is reciprocated by mechanism not shown in the direction of the arrows 3,046,653 Patented July 31, 1962 jaws 1 and 2 with the inner end of the bar in a predetermined position. tion, the ram 5 is at the opposite end of its stroke to that shown and commences to move in the direction of,

the arrow S towards a die-block 3. A follower roller 6 on a lever 7 then moves over a cam track 8a of a cam 8. The lever 7 is thus rocked and moves the clamp jaw 1 to clamp the bar M against the clamp jaw 2. The end of the trimming mandrel 4 upsets the end of the bar M within the die cavity 10 of the die block 3. When there is on the bar M a quantity of material upset by the trimming mandrel 4, which quantity is equal in volume to that of the required forging, the follower roller 6 reaches the end of the cam rise in the cam track 8 so that the lever 7 can rock to free the clamp 1 from the bar M. The ram 5 continues moving in the direction S and the trimming mandrel 4 is forced through the upset material in the die cavity 10 and with the aid of a cutting edge 11 of the die block, separates the upset blank portion of the bar from the remainder of the bar. The ram 5 continues to move in the direction S so that the face of the holder 12 of the trimming mandrel 4 engages the back face of the upsetting bushing 13 and moves this bushing in the direction S. The upsetting face, that is the lefthand face in FIGURE 1, of the bushing 13 is larger than the open face of the die cavity 10 and engages the preforged separated blank 9 in the die cavity and upsets it into the die cavity thus forming the material to its final shape. a

The depth of the die cavity may either be equal to the axial length of the required forging, or it may be less than that length. In the latter case a flange will be formed around the forging between the bushing and the die block.

Towards the end of the working stroke of the ram 5 the follower roller 6 engages a shifting stop 15 and is moved by it over a second cam track 8b which is at a different level to the cam track 8a so that the roller the die block, the upsetting bushing engages a stop 14' and is prevented from moving further in the directions with the ram and the trimming mandrel. The trimmingmandrel is thus withdrawn from the forging which is held back by the upsetting bushing and which falls from the machine. When the ram 5 reaches its starting position, the follower roller 6 is moved by the spring 16 back onto the cam track 8a since both tracks 8a and 8b are at the same levelat the point then engaged by the follower roller 6.

The clamp jaws 1 and 2 are thus open during the return stroke of 'the ram to allow of the bar end being fed forwards into the machine.

The bar M is fed by means of a clamp 22 actuated by a lever 20 which is pivoted at 21 and is connected by a link 17 to the ram 5. The end of the lever 20 carries a screw 19 on which is a nut 18 to which one end of the link 17 is articulated.

The extent of feed of the bar can thus be adjusted by rotating the screw 19 to move the nut 18 up or down and thus alter the effective length of the lever 20. The feed clamp comprises an abutment portion 22 and wedgeshaped jaws 23. The wedges 24 are mounted between the jaws 23 and the abutment 22 and are connected by links 26 to the lever 20. Springs 25 acting on the jaws 23 tend to separate them. During the working stroke of the ram the lever 20 will be rocked counter-clockwise as When the machine is put into operaseen in FIGURE 1 and will move the wedges 24 to the left as seen in FIGURE 3 so as to free the jaws 23 from the bar. This movement is also transmitted to the clamp which moves as a whole to the left. During the return stroke of the ram, the wedges 24 are moved to the right as seen in FIGURE 3 and wedge the jaws 23 against the bar so that it is fed to the right by the clamp.

The thin M is thus fed into its proper position before commencement of another forging operation.

FIGURE 4 shows an alternative arrangement for operating the clamp jaw 1. In this construction the follower roller 6 on the lever 7 is operated by a cam 28 mounted on the main operating shaft of the machine or on a shaft driven therefrom at the same speed.

I claim:

1. In a method of forging a metal ring and the like, the steps of clamping an elongated bar having a longitudinal axis in such a manner that an end portion of said bar projects through an opening into a die cavity in an axial direction; moving a mandrel member into said cavity against the projecting end portion of said clamped bar in a direction opposite to said axial direction to displace the material of said end portion of said bar in a radially outward direction about said axis until said material partially fills said cavity and forms an annular blank about said mandrel; further moving said mandrel member in said opposite direction and through said opening so as to sever said blank from the remainder of said bar, said mandrel member substantially conforming to said opening; and forcing said severed blank into said die cavity about said mandrel in said opposite direction until the blank is shaped into a ring conforming with said cavity.

2. A method of forging a metal ring and the like, comprising the steps of heating an end portion of an elongated bar having a longitudinal axis; clamping said bar in such a manner that said heated portion of. said bar projects through an opening into a die cavity in an axial direction; moving a mandrel member into said cavity against the projecting end portion of said clamped bar in a direction opposite to said axial direction to displace the material of said end portion of said bar in a radially outward direction about said axis until said material partially fills said cavity and forms an annular blank about said mandrel; further moving said mandrel member in said opposite direction and through said opening so as to sever said blank from the remainder of said bar, said mandrel member substantially conforming to said opening; and forcing said severed blank into said die cavity aboutsaid mandrel in said opposite direction until the blank is shaped into a ring conforming with said cavity.

3. In a method of forging a metal ring and the like, the steps of clamping an elongated bar having a longitudinal axis in such a manner that an end portion of said bar projects through an opening into a die cavity in an axial direction; moving a mandrel member into said cavity against the projecting end portion of said clamped bar in a direction opposite to said axial direction to displace the material of said end portion of said bar in a radially outward direction about said axis until said material partially fills said cavity and forms an annular blank about said mandrel, the volume of said blank being substantially equal to the volume of said cavity; further moving said mandrel member in said opposite direction and through said opening so as to sever said blank from the remainder of said bar, said mandrel member substantially conforming to said severed opening; and forcing said blank into said die cavity about said mandrel in said opposite direction until the blank is shaped into a ring conforming with said cavity.

4. In a method of forging a metal ring and the like, the steps of clamping an elongated bar having a longitudinal axis in such a manner that an end portion of said bar projects through an opening into a die cavity in an axial direction; moving a mandrel member into said cavity against the projecting end portion of said clamped bar in a direction opposite to said axial direction to displace the material of said end portion of said bar in a radially outward direction about said axis until said material partially fills said cavity and forms an annular blank about said mandrel; further moving said mandrel member in said opposite direction and through said opening so as to sever said blank from the remainder of said bar, said mandrel member substantially conforming to said opening; forcing said severed blank into said die cavity about said mandrel in said opposite direction until the blank is shaped into a ring conforming with said cavity; retracting said mandrel member and said ring in said axial direction; and axially advancing said bar into said cavity.

References Cited in the file of this patent UNITED STATES PATENTS 819,844 Briede May 8,1906 1,151,753 Bates Aug. 31, 1915 1,314,037 Amberg Aug. 26, 1919 1,456,597 Hughes May 29, 1923 1,714,661 Crawford et al. May 28, 1929 1,749,334 Georg Mar. 4, 1930 2,874,460 Riethmuller et al. Feb. 24, 1959

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