US3460370A - Apparatus for swaging continuous stock - Google Patents

Description

g- 1969 B. KRALOWETZ 3, 6 ,37

APPARATUS FOR SWAGING CONTINUOUS STOCK Filed May 9, 1967 2 Sheets-Sheet 1 FIG] wxwawxv' A OWN AVA g- 5 9 B. KRA'LOWETZ APPARATUS FOR SWAGING CONTINUOUS STOCK 2 Sheets-Sheet 2 Filed May 9. 1967 INVENTOR. @Rwuo KQAkO OGT'L.

US. Cl. 72405 8 Claims ABSTRACT OF THE DISCLOSURE At least two swaging units are arranged one behind the other in the longitudinal direction of the stock. Each swaging unit comprises only a single pair of diametrically opposite dies operable to reciprocate in and transversely to the longitudinal direction of the stock. Means are provided for operating said pairs of dies to blow in close succession but only one pair at a time.

Continuous casting plants increase steadily in importance as means for supplying stock to rolling mills. The casting is discharged from a continuous casting plant at a speed of about 1-15 meters per minute. Rolling mill trains operate at much higher rolling speeds. For this reason, rolling mill trains are not economical for rolling continuous stock which is received directly from relatively small continuous casting plants. It has already been suggested to arrange immediately behind the continuous casting plant a swaging plant, which require less power and structural expenditure than a rolling mill train and has an inlet speed equal to the speed at which the casting is discharged from the continuous casting plant. As the stock is swaged to one fourth to one sixth of it initial cross-section, the length of the stock and consequently the speed at which the stock is discharged from the swaging apparatus i increased to a value which corresponds to the receiving speed of a rolling mill train so that a sheetrolling train can be used behind the swaging apparatus with high economy.

A known swaging apparatus for use in succession to a continuous casting plant comprises at least two pairs of oscillating dies, which are equally spaced around the axis of the stock and synchronously driven by crank drives or eccentric drives and guided by a multiplicity of links in such a manner that the individual reciprocating dies perform during the effective part of their approach a movement toward the discharge end of the apparatu and by this movement advance the stock to be stretched, whereas they move back toward the receiving end while moving apart. Such apparatus is capable of effecting a large reduction in cross-section and a considerable stretching of the material. On the other hand, the structure is complicated and expensive and comprises a multiplicity of drive shafts, links and bearings, so that lubrication, cooling and sealing problems arise. It is desired to effect the entire reduction in cross-section of the stock in one such apparatus, if possible, and to arrange a plurality of similar units in series only if a larger deformation is desired. If the stock is subsequently to be entered into a sheet-rolling train or the like, a large stretching in one apparatus involves considerable disadvantages. The continuous stock which has been swaged emerges in surges at a speed which fluctuates between the receiving speed of the apparatus or the discharge speed of the continuous casting plant, and a multiple of that speed due to the deformation ratio. On the other hand, the speed at which the stock is fed to a sheet-rolling train or the like should be as uniform as possible. A further disadvantage resides in that a complicated unit requires conatent O 'ice siderable maintenance and the entire plant is stopped when this unit fails.

It is an object of the invention to eliminate these disadvantages and provide an apparatus for swaging continuous stock, which apparatus is simpler in design, requires only brief stoppages in the case of damage, and ensures a discharge of the swaged stock at an approximately uniform speed.

The invention is based on an apparatus which succeeds a continuous casting plant or the like and comprises at least two swaging units having dies which reciprocate in the longitudinal direction of the stock, and is characterized in that each swaging unit comprises only one pair of diametrically opposite dies, for swaging stock having a square cross-section the pair of dies of at least one swaging unit are spaced by an angle of from the pairs of dies of the other units, and the units are controlled to cause the pair of dies to blow in close succession, but only one pair at a time. The work of deformation is thus shared by at least two and preferably more than two swaging units, which are arranged in series, so that the stretching per die blow is relatively small and the full reduction in crossection which is required is effected by the total effect of the successive blows. As a result, the stock is discharged at a velocity which does not fluctuate between wide limits but which follows a fiat sine curve and which is sufiiciently uniform for feeding the stock to a sheet-rolling train or the like. As each swaging unit comprises only one pair of dies, the stock is increased in width, but this effect is compensated by the fact that one or more units have a pair of dies which are offset by 90 from the pair of dies under consideration. The individual swaging units are thus simplified in design and require less power. The swaging units may be manufactured in series at relatively low cost and held in stock so that any swaging unit which fails can easily and quickly be replaced while the entire plant is stopped only for a short time. The simple units do not require a complicated and time-consuming maintenance. When it is desired to swage a continuous stock having a flat rectangular cross-section in preparation for a rolling into sheets, the units act only on the faces of the workpiece so that an angular offset between the pairs of dies is not required. To reduce the space requirement a well as the costs, two or more swaging units may be arranged one behind the other in a common forging box, preferably together with a common drive motor.

In a development of the invention, the swaging units comprise as a carrier for each die a connecting-rod, which is driven in known manner by an eccentric shaft, which extends transversely to the axis of the stock and is eccentrically mounted in a rotationally adjustable housing, said connecting-rod is slidable in a guide which is rotatable on an axis that is parallel to the eccentric shaft, and the guide is held between hydraulic rams, which are parallel to the axis of the stock. These means have proved satisfactory in known swaging machines and are much simpler in design than the means for driving more than one pair of oscillating dies. As the connecting-rods are guided in the guides and the axes of the driving eccentric shafts and of the guides are transverse to the axis of the stock, the dies which are rigidly secured to the ends of the connecting-rods perform both a shearing movement toward the stock and an oscillating motion generally in the longitudinal direction of the stock about the axis of rotation of the guides. The rotational adjustment of the housings for the driving eccentric shafts enables a change of the depth of penetration of the dies into the stock and of the dead-center positions of the connecting-rods. The oscillating motion of the connecting-rods and dies in the longitudinal direction of the stock would not always be in accordance with the longitudinal and stretching movement of the stock. To ensure this agreement, the guides are not rigidly mounted but held between the hydraulic rams so that the connecting-rods can yield in the direction of the stock axis.

According to the invention, the bearing shell of the guide is slidably mounted relative to the rams and a compression spring is interposed between the bearing shell and each ram. When the bearing shell yields to one side and urges one ram back, the other ram need not follow this movement but the bearing shell remains gripped between the rams owing to the interposed springs.

According to another proposal of the invention, the adjustable housings of the eccentric shafts for driving the connecting-rods are backed in known manner on one side by an adjusting screw or the like and on the other side by a hydraulic ram, which acts as an overload release means, and a rotation of an adjustable housing due to overload in one swaging unit causes the same adjustment in the remaining units. When the swaging force in one of the swaging units exceed the permissible upper limit, the hydraulic pressure applied to the ram will be similarly increased. This pressure is continuously sensed by a suitable electro-hydraulic device, which in response to a pressure in excess of the preset upper limit causes a valve to open so that the pressure is released and the swaging force causes a rotation of the adjustable housings so as to move the connecting-rods and dies apart. This action will avoid damage to the swaging unit which is under an overload. To prevent damage to the remaining units as well as an abnormal swaging operation, the overall apparatus is controlled so that the adjustable housings of all units are adjusted at the same time to open their connecting-rods and pairs of dies. It will be understood that the entire plant can be stopped automatically.

The sharing of the deformation by two or more swaging units arranged in series has also the advantage that alloy steels, even high-alloy steels, as well as other metals which should not be subjected to a large deformation in a single pass can be swaged if the individual reductions in cross-section are property selected. In the known design comprising oscillating dies it has been found that such materials may be overstrained when being swaged. Within the scope of the invention, a plurality of swaging units may be combined in trains and two or more of such trains may be used in a series or parallel arrangement.

The invention is illustrated by way of example in the accompanying drawings, in which:

FIG. 1 is a view, partly in section, showing a swaging unit, and

FIG. 2 is an elevation showing five units forming an apparatus.

Each swaging unit comprises a pair of diametrically opposite dies 1, which are rigidly secured to the ends of connecting-rods 2, which slide in rotatable guides 3 and are driven by eccentrics. The eccentric shafts 4 and the axes of rotation of the guides 3 extend transversely to the axis of rotation of the workpiece strip 5 so that the rotation of the driving eccentric shafts 4 causes the connecting-rods 2 and the dies 1 to perform a shearing movement directed toward the stock 5 a well as an oscillating motion generally in the longitudinal direction of the stock. The guides 3 are provided with bearing shells 6. Pistons 7 on both sides of the guides extend parallel to the axis of the stock and are urged against stops by hydraulic pressure. The bearing shells 6 are extended to form sleeves 6'. Compression springs 8 are held between the sleeves 6' and the pistons 7 so that the guides 3 can yield in the longitudinal direction of the stock. When the piston 7 on one side is urged back against the hydraulic pressure, the piston 7 on the other side remains in position and the spring 8 causes the sleeve 6 and bearing shell 6 on this side to follow the movement so that the bearing shell is always guided and gripped.

The driving eccentric shafts 4 are eccentrically mounted in rotationally adjustable housings 9. A rotation of these .4 adjustable housings will change the dead-center position of the connecting-rods 2 and with it the depth of penetration of the dies 1. An adjusting screw 10 is provided for rotating each adjustable housing 9. The adjustable housings bear on the other side on a hydraulic piston 11, which serves as an overload release means. When the forging force becomes excessive, the hydraulic pressure acting on the pistons 11 will be correspondingly increased and an electro-hydraulic control device opens valves to reduce the hydraulic pressure so that the piston 11 can be forced back and the connecting-rods 2 and the dies 1 can be moved apart. Said electro-hydraulic control device may act at the same time to reduce the hydraulic pressure acting on the pistons 11 in the other swaging units so that the adjustable housings 9 in said units are also rotated to open the dies 1.

FIG. 2 shows five swaging units a-e forming an apparatus which succeeds a continuous casting plant and may precede a sheet-rolling train. The individual units are controlled in such a manner that the dies 1 of the units act in close succession but only one pair of dies blow at a time. It is apparent that units b and c are at an angle relative to units a, d and e so that the stock 5 is acted upon in a vertical direction by the pairs of dies of units a, d and e and in a horizontal direction by the pairs of dies of units b and c. Thus the pairs of diesof units b and c are at an angle of to those of units a, d and e so that the square stock can be acted upon on all four sides. The blow of the dies of unit a results both in a stretching of the stock and in an increase in the width of the cross-section of the stock. This increase in width is compensated and a further reduction in cross-section is effected by unit I). Unit 0 effects a further reduction in cross-section in a horizontal direction. Unit d and e compensate increases in a vertical direction and effect further reductions in this direction. Vertically and horizontally acting units may be arranged in alternation.

The pairs of dies in the units may extend at an angle of 45 to the vertical and horizontal directions. Two or more units may be accommodated in a common forging box, and a common drive motor may be provided for such group.

What is claimed is:

1. Apparatus for swaging continuous stock, which comprises:

at least two swaging units, which are arranged one behind the other in the longitudinal direction of the stock and comprise each only a single pair of diametrically opposite dies operable to reciprocate in and transversely to the longitudinal direction of the stock, and

means for operating said pairs of dies to blow in close succession but only one pair at a time.

2. Apparatus as set forth in claim 1, for swaging stock of square cross-sectional shape, in which at least one of said pairs of dies are at an angle of 90 to the rest of said pairs of dies.

3. Apparatus as set forth in claim 1, which comprises a forging box accommodating at least two of said swaging units.

4. Apparatus a set forth in claim 1, in which said means for operating said pairs of dies comprise a drive motor contained in said forging box and operatively connected to said pairs of dies of said swaging units contained in said box. I v

5. Apparatus as set forth in claim 1, in which said means for operating said pairs of dies comprise for each of said swaging units:

two rotationally adjustable housings,

two eccentric shafts, which extend transversely to the longitudinal axis of the stock and are eccentrically mounted each in one of said housings,

two rotatable guides,

two connecting-rods, each of which carries one ofsaid dies and is slidably mounted in one of said guides and operatively connected to one of said eccentric shaft to be driven thereby,

each of said guides being rotatable about an axis which is parallel to the eccentric shaft operatively connected to the connecting-rod mounted in said guide, and

two pairs of hydraulic rams, which are parallel to the longitudinal axis of said stock,

each of said guides being held between one of said pairs of rams.

6. Apparatus as set forth in claim 5, in which:

each of said guides is rotatably mounted in a bearing shell,

said bearing shell is slidably mounted relative to said pair of rams between which said guide is held, and

a compression spring is interposed between said hearing shell and each ram of said pair.

7. Apparatus as set forth in claim 5, in which each of said adjustable housings has associated therewith:

an adjustable stop engaging said housing and preventing a rotation of said housing in one direction in which said housing is rotatable to close said dies, and

means comprising a hydraulic ram engaging said housing and arranged to prevent a rotation of said housing in the opposite direction of rotation unless one of said rams is subjected to a pressure exceeding a predetermined limit.

8. Apparatus as set forth in claim 7, in which said adjustable stop comprises an adjusting screw.

References Cited UNITED STATES PATENTS CHARLES W. LANHAM, Primary Examiner 20 G. P. CROSBY, Assistant Examiner

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