DE1007601B - Drop forging press - Google Patents

Description

GERMAN

BIBUGTHEK (OesßEOTSCKEN) V PATENT OFFICE y

Forging hammers or forging presses are used for forging in the die. Both Forging hammers, the considerable forging pressure required for closed-die forging is achieved through implementation the kinetic energy of the beating bear in the deceleration pressure released upon impact. The forging press works in contrast with static pressure generated by a crank drive, toggle lever or the like, possibly also on hydraulic way is generated.

In recent times the closed-die forging press has been used to an increasing extent, mostly as a mechanical one Crank press is executed.

The usual closed-die forging presses have the actual work process of closed-die forging Adopted unchanged from the forge hammer developed earlier. So there are two tool halves, the upper and lower dies, used in the work surfaces facing each other the engravings are provided. The heated blank is placed on the engraving of the lower die and then the press ram carrying the upper die is lowered so that it covers its entire working surface hits the lower die. As with a hammer, the forged piece is all at once over its entire length Deformed surface. A thin burr is then driven out around the entire circumference of the forging.

Very large pressing forces are required for such a forging process. These require high forces correspondingly heavy and expensive machines. Mainly on the extraordinary high acquisition costs of the closed-die forging presses of the usual design is their further spread up to now failed.

In order to avoid these high pressing forces, it has already been proposed not to use the pressing pressure to act simultaneously over the entire surface, but by rolling a curved one Die on a likewise curved or straight die during the pressing process focus on a limited zone of the forging that occurs during the pressing process migrates over the entire surface of the forging.

To implement this idea, so-called forging rolls have been developed at where two swaged rollers or parts thereof roll off one another under pressure. By However, the forging usually comes out of the forging in a freely floating manner due to the curvature of the two dies both die halves and can therefore not be exactly dimensionally in its longitudinal extension. In the case of simple forgings, such as staples closed-die forging presses

Applicant:
Beche & Grohs

Company with limited liability,
Hückeswagen (RhId.)

Dipl.-Ing. Hans Bech6, Hückeswagen (RhId. '
has been named as the inventor

or pitchforks, this is not a disadvantage. However, if the forging is more intricate, it stays in place

hang the lower die bent in such a way that it is true to size, however, it is arched. It is difficult to straighten such a forging afterwards and awkward. The well-known forging rolls, which already have a geared connection two engravings rolling on one another have been provided, are therefore solid for forging outlined and straight precast elements not suitable.

Another suggestion to implement the idea outlined above to reduce the high Press forces uses a flat lower die and a curved upper die, which is on rolling off the blank carried by the lower die. This facility makes the pressing large parts, especially if the pieces to be pressed are relatively thin. To the Drop forging of complicated objects, as already done with the forging hammer in the drop can be forged, this device is not useful because the dies in their location to each other, as they correspond to the finished drop forging, not when pivoting the upper die are set. Due to the side forces that occur during the production of forgings rather, the dies slightly shifted in their position to one another, creating a forging with sideways Staggered parts arise, which is unusable.

In contrast, the device according to the invention is intended for forging in the die in the strict sense serve that word. So it should be a forging of possibly complicated shape by a walking movement, by which a back and forth movement is understood, which one Material flow to the two opposite ends

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of the die causes in a well-defined die be kneaded. The finished forging should be accurate true to size and straight can be removed from the die. To achieve this goal are at a device of the type described last, according to the invention, the dies for securing a pure Rolling movement of their contact surfaces on each other by a gear independent of the press drive necessarily coupled back and forth across the pressing direction. First the inevitable and in the same sense of movement movement of the dies ensures that the engravings of both die halves during this movement are exactly opposite each other, so that an identical forging is produced as in forging with a hammer or the usual forging press with transverse to the pressing direction immovable dies. However, the force to be used is in the device according to the invention only a fraction of the previously required pressing pressures. Usually only about a quarter up use one seventh of the previously required pressure. As a result, the invention builds Forging press much lighter and cheaper.

In the drawing, an embodiment of the invention is shown schematically, namely Fig. 1 shows a side view of the press and Fig. 2 shows a section through the upper part of the press. In the embodiment shown, the lower die α is, as usual, flat. It bears the die engraving on its upper side. The lower die is attached to the table b , which is slidable in a flat guide on the correspondingly widened top of the plunger c. This is guided in a cylinder provided in the machine frame and can be raised and lowered by a gaseous or liquid pressure medium. In addition to the press, a motor-connected crank mechanism d is provided, which is connected to the retracted cheeks of table b by push rods e , so that table b with the lower die a attached to it can be moved back and forth in its guide by the crank mechanism .

The upper die / is arched, namely as a circular arc, the radius of which goes through the pivot point g. The upper die entered by the lever h swings around the pin g. The oscillating lever h is also via two push rods e that on lateral bearing lugs of the rocking lever engage (Fig. 2) connected to the crank mechanism d.

When the crank mechanism is actuated, the upper and lower dies rotate in the same direction and are in the same direction Amplitude moved back and forth.

For drop forging, the heated blank is placed on the lower die α . The ram c then moves up with slight pressure until the blank between the lower die α and the upper die / is grasped. Then the crank mechanism d is switched on and the pressure on the ram c is increased. During the pressing, the crank mechanism remains in operation, so that the heated blank is, as it were, kneaded into the engravings of the dies. The pressing takes place only on a narrow strip of the upper side, the width of which mainly depends on the radius of curvature of the upper die / and which moves back and forth over the blank during the pressing process. Advantageously, the pressing does not take place in one go, but with the progressive lifting of the punch c while the dies move back and forth.

The pressing pressure can be generated in any way, either mechanically or hydraulically. It is essential that the pressing pressure can be increased when going back and forth of the dies.

Claims (1)

PATENT CLAIM: Device for deforming in the die, the upper and lower dies provided with engravings are pressed against each other by means of a press and a curved upper die opens rolling off the blank carried by the flat lower die, characterized in that that the dies to ensure a pure rolling motion of their contact surfaces on each other by a gear that is independent of the press drive, inevitably going back and forth transversely to the pressing direction are coupled. Considered publications: German patent specifications No. 367 534, 204 729, 203 105, 36 494; French patent specification No. 689 116 (with additional patent specification No. 39540), 530 178, 345 728; U.S. Patent Nos. 2,654,277, 239,245. 1 sheet of drawings © 7 »507/25» 4.57