DE2131013C2 - Drawing press - Google Patents

Description

a) the intersection point P of the main axis V and the minor axis W of the coupling curve lies in the side of the ram movement path F and häf a smaller distance from the lower end point V of the main axis V than from the upper end point V _{2 of} the main axis V;

b) the coupling curve is intersected by two sectors Si and 52 from the ram movement path Fin, the sector S ₂ which encloses the largest length range of the main axis V of the coupling curve being on the side of the ram movement path F which faces away from the drive crank and where for the Dimensions of the two sectors Si, S ₂ apply:

4, drawing press according to one of claims 1 to 3, characterized in that the link (98, 202) finely closes an angle qzn of the ram movement path with its counter-rotating stroke movements which is always below 30 °

5, drawing press according to one of claims 1 to 4, characterized in that the coupling point C is at a smaller distance from the point b than from the point a.

6, drawing press according to one of claims 1 to 5, characterized in that the coupling point C lies between a and b

7, drawing press according to one of claims 1 to 6, characterized in that the distance between the center O of the drive crank (80, 208) and the ram movement path F is at most three times the crank offset

a _t : b \> 1
m: n> \

35

where äi is the largest vertical dimension of the sector Si b \ facing the drive crank, the largest horizontal dimension of this sector Si, m is the largest vertical dimension of the sector S ₂ facing away from the drive crank and η is the largest horizontal dimension of this sector S ₂

characterized by such a design of the articulated gear that for the coupling curve the following additional conditions are met:

c) the end point V located in the lower stroke area of the ram (114, 200) of the main axis V of the coupling curve is at a smaller distance from the ram path F than the end point V _{2 of} the main axis located in the upper stroke area of the ram;

d) the main axis V of the coupling curve is inclined towards its lower end point V \ towards the drive crank (80, 208) and intersects the plunger movement path F below the coupling curve at an angle K that is greater than 120 °.

60

2. Drawing press according to claim 1, characterized in that the center O and the articulation point D lie one above the other on the same side of the ram movement path F at a distance.

3. Drawing press according to claim 2, characterized in that the points O and D lie vertically one above the other on a straight line parallel to the ram movement path F.

The invention relates to a drawing press of the type mentioned in the preamble of claim 1

The known mechanical press drives generally have a drive crank which the Press ram drives directly via a connecting rod or a handlebar The use of such Press drives, however, are particularly subject to tight economic limits in the case of large-scale presses one z. B. assume that a standard press with mechanical press drive for the work process an approximately constant pressing force of 200 t over a working stroke of 152 mm is required and that the With a total stroke of 406 mm, press its nominal force at about 12 mm from the lower end of the stroke from delivers, it can be shown that such a press only has about 35 to 40% of its nominal force on a Position that is 152 mm above the lower end of the stroke when the crank torque has its maximum value. A higher load at this working point inevitably leads to a Overload of the drive crank, its reduction gear and those arranged in the drive train of the press Coupling. Therefore, in order to obtain the desired pressing force of 200 t at the beginning of the working stroke, one would have to a press drive designed for a capacity of 5001 can be used here. This would go without saying be extremely inefficient, since such a press over most of its stroke a would be able to deliver a pressing force exceeding the required! / 200 t. In addition, one would have to Press received an extremely large and complex press frame.

In order to remedy the mentioned difficulties and disadvantages, there have been numerous in the past Press drives developed. But it has been shown that it is extremely difficult with a mechanical Press drive to remedy the existing disadvantages and a mechanical press drive with cheaper To create operating characteristics with a view to achieving high production speeds the ram speed when approaching and The return stroke is as large as possible, while the working stroke is comparatively small, and the further via the Working stroke there is a favorable force curve on the press ram. In addition, the drive should be a Have the lowest possible input torque over a large working stroke, so that the dimensions

the clutch and the crank are kept as small as possible can be

Drive devices that work with control cams, meet the requirements mentioned to a certain extent. However, such drives are due to the high specific surface forces for long-stroke high-performance presses working with high pressing forces, to which the invention is directed is unsuitable.

In the case of drawing presses, there is still another requirement, which is the development of a powerful mechanical press drive made more difficult. Most metals must namely with a Speed that is below a known maximum value for steel this maximum speed value is about 0.46 m / s. With a pull stroke of 152, the Ram speed on the last 152 mm of the entire downward stroke not higher than 0.46 mm / s lie. To do this with a conventional crank press, the speed of rotation must be the Driving crank can be reduced accordingly. Since one turn of the crank corresponds to a full press cycle, accordingly, the operating speed of the press becomes due to the slow running during the pulling stroke degraded

Crank presses have been known for a long time in which the drive crank has a multi-link Link gear acts on the press ram in order to achieve the periodic working movement of the ram. Among the various articulated gears, those are also known in which the one with the ram connected handlebars in the coupling point connected to a coupling lever driven by the drive crank is on which a rocker arm articulated on the press frame engages (GB-PS 3 97 558, GB-PS 4 24 59 !, magazine "Das Industrieblatt", Stuttgart, January 1959, page 19). These mechanical press drives but have an unfavorable operating characteristic. Your articulated gear is designed so that the is to improve in terms of their operating characteristics so that while maintaining the desired high Ram speed during the approach and return stroke and with the required smaller ram -? - speed during the working stroke in particular for the Drawing process favorable course of the pressing and side forces is achieved.

This object is achieved with the features listed in the characterizing part of patent claim 1

in It could be established that since long-known mechanical press drives with multi-link articulated gears with appropriate Coordination of the gear parts can achieve an operating characteristic of the press with the hitherto at best hydraulic presses was achievable. In particular, it is possible at high ram speed via the Approach and return stroke the force curve over the itself with significantly lower ram speed to significantly improve the working stroke. A change in direction of the lateral forces on the working stroke and the resulting disadvantages, particularly with regard to product quality ν:, <den avoided. In addition, it is achieved that the Seiteniefte at the beginning of the plunger return stroke have a falling course, which in view of the perfect separation of Tool and workpiece is advantageous. The size of the side force can be determined from that area of the Set the coupling curve, which includes the working stroke, considerably smaller than in the other area of the Coupling curve showing the return stroke and the approach stroke with the dead center in between When the ram approaches the end point of the working stroke, the lateral force of the ram has a falling course, whereby the undesired frictional forces between the workpiece and the tool of the Reduced ram and the separation of the tool from the workpiece are favored. The diminution the damaging frictional forces between tool and workpiece lead to considerably better

Lateral force acting on the ram over the working stroke 40 product qualities and also enable higher product qualities not only very strong in their size, but also in their press speeds and press forces.

Direction changes and also further when the ram approaches the end of the working stroke increases. The change in direction of the side force in the course of the working stroke leads to a toggle lever effect between the ram and the ram link and also impairs the working or pulling process in unfavorable way. The lateral force on the ram causes a greater or lesser degree during the working stroke large lateral ram deflection, which has a detrimental effect on the machining accuracy during the drawing process affects. This applies if the lateral force changes in size and / or during the working stroke Changes direction. There is an increase in the lateral force as the ram approaches the bottom dead center also disadvantageous, since the friction between the workpiece and the ram or his on the working stroke Tool increases and a simultaneously increasing ram lateral force results in a considerable increase in friction and at the same time causes an increase in the plunger deflection, which is detrimental to the uniform and accurate metalworking impacts. In this respect it is also unfavorable if the lateral force is at Beginning of the backward or upward stroke of the ram

continues to rise, since in this phase the separation of the 65 must be designed in such a way that while avoiding abrupt The ram takes place from the workpiece. The pressing force on the working

The object of the invention is to provide a drawing press that has a stroke towards the end of the working stroke equipped with an articulated gear of the known type, which leads to a

In addition, the inventive design of the press drive or its articulated gear also an extremely favorable speed

Achieve keits- and pressing force curve of the Siößels on the working stroke. The press drive can be in design its operating characteristics in such a way that the ram speed over the working stroke is a constant, undergoes uniform reduction, with it up to

so at the end of the working stroke and beyond that it steadily drops down to dead center. This advantageous speed characteristic while avoiding abrupt changes in the slide movement leads to a reduction in the unfavorable frictional forces and consequently: an improvement in the pulling process. With regard to the reduction of the frictional forces, it is also important that the pressing force changes as evenly and steadily as possible over the working stroke of the ram, since sudden changes in the pressing force considerably increase the frictional forces and also lead to increased wear on the press in its tools. The invention creates the possibility of making the operating characteristics of the press drive extremely favorable in this respect as well

corresponding decrease in the ram lateral force and thus an improved product quality at the same time Increases the service life of the press parts.

In the case of the press drive according to the invention, the articulated gear can be of different designs. For example, the articulated gear, as specified in the literature "Das Industrieblatt", 1959, page 19, Fig. 8, be designed in such a way that the coupling point c is at the end of the coupling lever, with the articulation connection b of the rocker arm on the coupling lever in a smaller one The distance from the coupling point is greater than from the point a at which the drive crank is connected to the coupling lever. On the other hand, the coupling point c can also lie between the points a and b on the coupling lever. The center O and the articulation point D can lie one above the other on the same side of the ram movement path F in the case of the articulated gear mechanism. In this respect, the linkage is in his

Structure vpränrjprhar Wpspntlirh is that Hip CiPtriehe-

parts are coordinated so that the named Coupling curve is reached. The measures listed in the subclaims contribute to this. the aforementioned to further improve favorable operating properties of the press drive.

The invention is described below in connection with the exemplary embodiments shown in the drawing explained in more detail. In the drawing shows

1 shows a press of the type according to the invention in a side view, partly in elevation:

F i g. 2 the press according to FIG. 1 in front view;

F i g. 3 shows a cross section along line 3-3 of FIG. 1;

F i g. 4 is a partial view of the in the press according to FIGS. I to 3 used for the press drive Articulated gear;

Fig. 5 to 8 show schematically the articulated gear Press according to FIGS. I to 4: n different working positions ν uring a full working cycle;

9 on a larger scale schematically shows the in Connection with the F i g. 1 to 8 shown press drive together with its coupling curve;

Fig. 10 shows the coupling curve of the aforementioned Press drive on a larger scale:

11 schematically shows the articulated gear in a position of the coupling curve in which a maximum ι jbertragungswinkel is available;

F i g. 11 a the linkage according to FIG. H in one other work position:

12 shows the articulation system in a position in which the smallest possible transmission angle present:

Fig. 12a the (/! Steering gear schematically for illustration another work characteristic:

13 to 15 different diagrams for illustration the operating characteristics of the press according to the invention:

F i g. 16 schematically shows a further exemplary embodiment a press drive of a press according to the invention;

F i g. 17 shows a geometrical representation of the linkage.

The in the F i g. 1 and 2 as a whole, the drawing press has a vertical press frame A, a press drive B with an articulated gear C. The press frame A includes a foot part! 10, which receives a vertically arranged billet container 10a and is embedded in the foundation so that its top is level with the bottom surface 11 of the foundation. Arranged on the foot part 10 are two vertical box-shaped uprights 12 and 14, which are connected at their upper ends via a three-part crosshead 16, which consists of three rectangular box parts 18, 20 and 22. The articulated gear is mounted on the crosshead 16 in such a way that the planes of division between the box parts 18, 20 and 22 coincide with the main joints of the articulated gear C, which facilitates manufacture and assembly

ίο be.

The main parts of the press frame A are connected to one another by six vertical tie rods. As shown above all in FIGS. 1 and 3, two anchor rods 24 each with a large diameter extend through the two uprights 12, while in each case an anchor rod 26 with a smaller diameter extends through the front upright 14. The anchor rods 24 lie at equal intervals on the opposite sides of the main articulation points of the articulated gear, which are designated by D and R O in the orientation. The anchor rods 24 absorb the reaction forces of the press forces. In contrast, the anchor rods 26, which are smaller in diameter, only absorb a small proportion of the reaction forces; they serve

2ϊ primarily the absorption of the transverse or lateral forces exerted by the press ram. The individual components of the press frame A are at different points on their superposed surfaces, such. Wedged at location "" x 28 in Figures 1 and 2 to provide a transversely rigid frame.

The uprights 12 and 14 limit the path of movement of the press ram 114. At the inner edges of the Stand 12 and 14 are ram guide strips 12 'and 14' for guiding the press ram 114 in its Vertical movement provided.

The press drive is on the side next to the press a special table or support frame 30 is arranged. It has an electric motor 32 which has a Coupling 34 is connected to a drive shaft 36.

on which a large diameter flywheel 38 sits. The flywheel 38 and the shaft 36 are in bearings 40 rotatably mounted. On the flywheel 38, a pressure medium-actuated high-performance clutch 44 is more conventional Type of construction stored over which, when switched on, the flywheel is connected to the main drive shaft via the shaft 46 42 is drivingly connected. The shaft 46 is mounted in bearings 48 of the frame 30.

The gear train of the press drive is housed in a two-part gear box 52. The drive shaft 42 extends transversely through the gear box 52 and carries a brake 50 at its outer end. The shaft 42 is mounted in shafts which are located in the dividing plane of the gear box 52. The transmission, which has a transmission ratio of 150: 1, has a main drive wheel 54 seated on the drive shaft 42 with which a gear wheel 56 meshes, which is seated on a shaft 58 which is mounted in bearings in the transmission housing 52. On the shaft 58, on both sides of the gear 56, sit two gears 60 which mesh with gears 62 which are keyed on a drive shaft 64. The drive shaft 64 protrudes at both ends over the sides of the press frame A , the two main gear wheels 66 being seated on the outer ends of this shaft.

The gears 66 are each in mesh with a heavy gear 68 of large diameter, which, as Fig.3 shows, consists of an annular

Ring gear. 70, which is welded to two Sfirnplatten 72. which in turn are connected to a central hub 74 which is rotationally connected to a stub shaft 76 which is mounted in the crosshead 16 of the press. Fig. I shows that the two stub shafts 76 are mounted in the parting plane between the sections 18 and 20 of the crosshead, bearing sleeves 78 being used for mounting. According to FIGS. 1 and 4, the inner ends of the stub shafts 76 are wedged with two crank parts 80 which are connected via a crank pin 82. These parts thus form the drive crank of the press drive, the crank offset being equal to the distance between the center or stub shafts 76 and the center line a of the crank pin 82.

The articulated gear C consists according to FIGS. I to 4 from a coupling lever 84 which is articulated by means of a split cap 83 to the crank pin 82 of the drive crank at the hinge point a. The coupling lever 84 is designed in two parts, its outer end being delimited by a cylinder part 86 which has a slot 87 which receives the coupling lever 84 and is connected to it by means of a pair of bolts 87a. Two rocker arms 88 are articulated with their one end at the hinge point D on a horizontal axis 92 which is arranged in the upper region of the press frame A between the sections 20 and 22 of the crosshead. The articulation point D lies vertically above the center of the drive crank or its stub shafts 76. The vertical straight line passing through the two points O and D runs parallel to the vertical movement path of the plunger 114.

The outer ends of the rocker arms 88 are split caps 90 with the cylindrical end portion 86 of the coupling lever 84 connected, whereby a joint connection between the levers 88 and 84 is created whose effective joint center point is formed by the center point of the cylindrical part 86.

A hinge pin 94 extends transversely to the cylindrical part 86, at a distance L from its center, which protrudes on both sides over the cylindrical part 86 and is connected by means of a cover 95 with the forked outer end to the connecting rod 98 of the tappet 114, which forms the connecting rod . The lower end of the link 98 is articulated to the plunger 104 which, during operation, moves over the plunger movement path F (FIGS. 5 to 9). The articulated connection takes place by means of a hinge pin 100, which is held between two cheeks 102, which extend upwards from a horizontal plate 103 of the plunger 104.

The plate 103 of the plunger 104 is via a

Part 8C (crank offset): Part 84 '
Part 84 '
Part 88 '
Part 98 '

With the aforementioned length ratios, the maximum that can be applied over the 914.4 mm working stroke Torque roughly equal to 1674 mt, while that's about motorized plunger adjustment screw 106 adjustably connected to the plunger. This adjusting screw holds through a threaded opening of a component 108, which sits in the lower end of a sleeve 110, the one Slideway for the part 103 forms. The sleeve 110 is closed at the lower end by means of a plate 112, which carries the actual plunger part 114. The latter consists of an outer housing 116. which pressure blocks 118 and 120 encloses. Of the

in the actual drawing ram 122 and the pusher 123 are releasably connected to the lower plate 124, which in turn is connected to the housing 116.

The mode of operation of the above-described press drive can best be seen in FIGS. 5 to 8

r>, in which those components that are compatible with the Components of the press according to FIGS. I to 4 match, provided with the same reference numerals which, however, have an index line here to distinguish them.

F i g. 5 shows the link mechanism with the drive crank in a position in which point E, at which the press ram is hinged to the link 98 ', is in the top dead center position. The drive crank rotates clockwise, and in the illustrated arrangement of the articulated gear, the upper dead center position is set at an angle of rotation of the drive crank of approximately 55 °. When the drive crank rotates further from the position shown in Fig.5 rotational position, the point E is moved in the drawing stroke downward, he g the position shown in F i. 6 runs through. In this position, the drive crank is in a rotational position of around 200 °.

When turning from the position according to FIG. 6 to the position according to FIG. 7, the plunger pivot point E continues to move downwards, the full pulling stroke being carried out and the point f passing through the point of maximum pressing force at a crank angle of rotation of about 254 ° . In Fig. 7 (crank angle of rotation of about 320 °) the ram is in its bottom dead center position. Subsequently, on the return stroke of the ram, the Geienkg gear passes through the position shown in Fig. 8.

Example I.

In the embodiment chosen here, the press is designed so that it has a total stroke of 3327 mm, a working stroke of 914.4 mm against a constant load resistance of 3265 t (pulling stroke) and a working stroke of 1060.4 mm against a constant load resistance of 1088.4 t (push-through stroke) having. To achieve this, the length ratios of the various lever connection parts preferably chosen as follows:

Distance O to α = 1524 mm
Distance α to b = 2286 mm
Distance b to C = 762 mm
Distance b to D = 3048 mm
Distance C to E = 4572 mm
Distance O to Z) = 3048 mm
Distance O to F = 2438.4 mm
Distance α to C = 3048 mm

the torque applied to the 1060.4 mm working stroke is about 1355 mt. The press frame needs here to be designed for a load of 97951 only.

These values are considerably below those of the conventional press crank drives which do so are designed so that they can perform the same work functions. In these cases there is an almost three times greater torque with two to one and a half times higher load on the press frame a. This Fig. Example is shown in Fig. 9 shown.

Example II

A rapid approach and return stroke speed with a slow ram speed at the same time the working stroke can be with the same or with one

should have a larger or a smaller total stroke with corresponding io, the length ratios as according to the change in the length specified above:

achieve relationships. If z. B. the press has a total stroke of 406.4 mm, a working stroke of 152.4 mm against a constant load of 181.4 t

Part 80 '(crank offset): Distance O to a = 239.7 mm Part 84 ' Distance α to b - 420 mm Part 84 ' Distance b to C = 184.4 mm Part 88 ' Distance b to D = 719.6 mm Part 98 ' Distance C to £ = 1085.1 mm Distance O to D = 815.6 mm Distance O to F - 4! 8.6 Him Distance α to C = 604.5 mm

The angle between the line OD and the slide path F is 7 ° here and the distance OF is measured at right angles to this line between the axes O and D.

It should be noted that in this l-'all the general Articulated lever arrangement the same as in the embodiment according to FIGS. 5 to 8, however, the in Leverage ratios differ. Even with these leverage ratios, the ram advance and return stroke movement a rapid traverse movement, while the ram over the 152.4 mm working stroke at constant angular speed the drive crank executes the desired slow lifting movement. The maximum torque here is about 16 128 mkp.

Operation of the embodiment II

In order to clarify the method of operation, reference is made to FIG. 9, in which the according to Example II designed drive system is shown schematically. For the sake of simplicity and clarity, the different lengths and axes here designated as follows:

first joint part:
second joint part:
third joint part:
Crank:
first axis:
second axis:
third axis:
fourth axis:
fifth axis:
sixth axis:

Handlebar 98
Coupling lever 84
Rocker arm 88
Crank 80
Axis E
Axis O
Axis a
Axis C
Axis D
Axis b.

45

50

55

When the crank 80 rotates in the direction of arrow R according to FIG. 9, the fourth axis C, which forms the coupling point, moves over the coupling curve, which determines the movement of the first axis E along the tappet movement path F. The course of the coupling curve is determined so that the ram moves first in rapid traverse in the direction of the working stroke, then with a slow stroke movement over the working or pulling stroke and finally in rapid traverse over the return stroke to the top dead center position TDC. In Fig. 10 the coupling curve is shown separately. The coupling curve is intersected by the tappet axis or the line on which the tappet moves and is thus divided into two sectors, one sector being essentially the lowest stroke position of the tappet and the other sector being essentially the movement of the tappet in the upper stroke range is equivalent to. Those points V \ and V2 of the closed coupling curve which have the greatest distance from one another are connected to one another by a straight line which forms the main axis V of the coupling curve. The minor axis W is drawn in perpendicular to the main axis and connects those points of the coupling curve which have the greatest mutual distance perpendicular to the main axis. The main axis V and the minor axis W intersect at point P. The relationships between the various sectors, the major and minor axes and the various positions of the articulated gear are important for the working characteristics of the press drive and are explained in more detail below.

The second sector of the coupling curve encloses most of the main axis. This sector lies on that side of the ram path F which faces away from the crank 80. The second sector relates to the rapid traverse movement of the ram and also corresponds to the movement of the ram in the upper stroke range. Since the second sector is located on the side of the ram path F facing away from the crank, when the crank moves in the direction of the coupling curve, a high speed is generated. This rapid speed is increased by cranking the crank to the other side or to the side opposite the ram path F. In this way, the cranked crank causes a rapid traverse movement when point C is in the second sector.This rapid traverse movement occurs during the ram movement in the direction of the top dead center position TDC as well as in the opposite direction.

The second sector of the coupling curve has the vertical height dimension m and the horizontal width dimension n. In order to achieve a rapid upward movement of the ram, the height dimension m is larger than the width dimension n. Correspondingly, the first sector of the coupling curve has a height dimension a 'and a width dimension ö 'on. The height dimension a '

is larger than the width dimension b '. Since the width dimension b 'determines the size of the lateral or transverse force of the ram during the pulling stroke, it should be kept as small as possible. In practice, the ratio of a ': b' is generally above 1.5: 1.0. The ratio of m : π is greater than 1.0, and preferably greater than about 1.5: 1.0. These dimensional relationships of the two sectors of the coupling curve cause the rapid upward gear (return stroke) and the high tappet force in the downward gear or in the working stroke with the smallest possible lateral force. The side force is generally less than 10% of the total force generated on the ram.

By offsetting the drive crank with respect to the ram movement path F, a more straightforward upward and downward movement of the link 98 during the pulling stroke can be achieved. If the crank were arranged in direct alignment with the tappet movement path F, a toggle lever action would result in which the link 98 would inevitably carry out a wide swing-out movement in the vicinity of the bottom dead center position. This would lead to considerable lateral forces and, accordingly, to considerable wear on the slide guides. As the F i g. 9 and 10 show, the main axis V of the coupling curve intersects the ram movement path F at an obtuse angle k. This angle should be greater than approximately 110 ° and preferably greater than approximately 120 ° in order to ensure that the K & ppelkurve with respect to the ram movement path F has an approximately vertical course.

Further operating properties of the drive according to the invention are shown schematically in FIGS. 11, 12, 11a and 12a. The angle q drawn in FIGS. 11 and 12 is the "transmission angle" of the lever system. When this angle is around 90 °, the most efficient power transmission occurs. If, on the other hand, this angle is relatively small, the most effective transmission of motion results. According to the invention, the transmission angle q is as in FIG. 11, it is greatest when the plunger moves on the working stroke in the direction of its bottom dead center position BDC. The drive has the desired, most favorable power transmission ratio. According to FIG. 12, the angle q is smallest when the coupling point C moves over the second sector of the coupling curve. In the exemplary embodiment shown, this is the case when the most favorable motion transmission conditions are present. According to the preferred exemplary embodiment of the invention, the angle q should not decrease significantly below 40 ° in order to avoid an excessively high slide acceleration and excessively abrupt changes in the slide acceleration.

Fig. 11a shows that the coupling curve is divided here by the ram path F into the two sectors mentioned. 1 la, the crank 80 overlaps the coupling lever 84 or the coupling lever lies in the crank plane. This has the consequence that the point C moves only slowly in the vertical direction when passing through the bottom dead center position BDC Working or pulling speed The point C is, as mentioned, in the first sector of the coupling curve and is immediately ready to begin the downward movement to the bottom dead center. This increases the power transmission and adjusts the operating characteristics of the drive system in the desired manner. A further characteristic of the drive is shown in FIG. 12a. The Kurbe! 80 and the rocker arm 88 have two positions in which they are parallel to each other. If the main axis of the coupling curve have the two end points V'i and V ₂ at the point of intersection with the coupling curve and if, as fully indicated, the crank 80 and the rocker arm 88 are parallel to one another, the coupling point moves down along the coupling curve, where he is at a considerable distance from the two Sr 'nittpunkte Vi and V ₂ . In the other parallel position, which is shown in phantom in FIG. 12a, point C is further removed from one of the two points K ₂ , Vi. The rapid traverse movement of the lever system is mainly given between these two parallel positions and over the area of the upward movement of the Konpelnuiiktes C. along Her Knnnelkurve. The point V ₂ lies immediately in front of the lower dead center βDC of the coupling point C when this moves along the coupling curve to the point BDC.

If a press is equipped with an articulated gear, which one or all of the in Fig. 10, 11,12,11 a and 12a shown working characteristics has, a particularly powerful press can be achieved. Achieving all of these Features on a single press result in the most effective application of the invention.

Some further features of the invention are explained in more detail below: As already mentioned above, the crank 80 rotates about the center O, which is laterally offset with respect to the slide path F of movement. The rocker arm 88 swings about the upper point D over an arcuate path. The center O of the crank lies vertically below point D, so that the rocker arm 88 moves essentially over a path which approximately corresponds to the coupling curve. Since the crank is connected to the end of the coupling lever 84, the coupling lever 84 is alternately subjected to compression and tension when the crank is turned. This results in an effective movement.

«And power transmission, which is influenced by the characteristics of the handlebars of the swing arm 88 hanging down. The main part of the coupling curve, which extends over the larger length range of the main axis V on one or the other side of the ram movement path F, is on the side of F that faces away from the crank axis the crank axis and the ram of the press on a continuous course. The point b lies at a smaller distance from the point C than from the point a. In this way, a favorable power transmission is obtained during the last part of the downward movement of the ram. All of the aforementioned features are important for the invention and contribute to improving the operating characteristics of the press.

In Fig. 13 a diagram is shown which in

Comparison of the operating characteristics of a press according to the invention and that of a conventional one Drawing press represents If z. B. the maximum drawing speed for steel is about 0.46 m / s and the Press should have a total stroke of 406.4 mm and a pulling stroke of about 152.4 mm, so may during the last 152.4 mm of the ram stroke the speed

speed of the ram does not exceed the value of O / iSm / s exceed. The solid lines relate to a press of the type according to the invention, while the unis in dashed lines relates to a conventional crank press. With the previously known Press the crank speed is reduced to twenty-one revolutions per minute, so that the Speed over the last 152.4 mm stroke range does not exceed the speed value of 0.46 m / s It goes without saying that the downward and upward movement of the ram is the same Complete the speed curve.

The situation is different with the drive according to the invention. The crank speed can be increased here to sixty revolutions per minute without the ram speed during the pulling stroke exceeding the speed value of 0.46 m / s. During the movement of the plunger from the bottom dead center position SDCzu the top dead center position 7 "DC he follows the upper curve a, whose maximum speed is about 2.6 m / s at the downstroke of the press according to the invention, the speed curve b with the section I, via the speed increases to approximately 1.2 m / s and then drops over the working stroke to about 0.46 m / s. Then curve b changes over to the second section II, in which the speed is in the range of 0.46 m / s is In section III the curve then goes back from a speed value of 0.46 m / s to the value 0. It can be seen that the press according to the invention can work considerably faster than the previously known press approaches the value of about 0.46 m / s, it is expected that the speed of the press will be reduced by about 10% to fifty-four revolutions per minute g, which has the operating characteristic of Fig. 13, operates about 2.6 times faster than a conventional press. The increase in production speed is accordingly about 157%.

14 shows a further diagram in which curve a relates to a known press which is said to have a ton output of approximately 200 t over its entire working stroke of 152 mm. It will be appreciated that the actual tonnage output t exceeds If the previously known press to a maximum tonnage output of approximately 8001 decreased such a press in the region of bottom dead center position about 1700, it would over the drawing stroke according to curve b a tonnage output result, the significantly lower the required nominal value of 200 t is. The curve c gives the values of a press according to the invention. In this case there is a pressing force of about 800 t in the area of the bottom dead center if the pressing force over the pulling stroke of the press is about 200 t. From the comparison of these curves it can be seen that the load peaks in a press according to the invention are considerably lower and that the press according to the invention can thus have a press frame which can be built much lighter than that of a conventional press.

15 shows another operating characteristic of the press according to the invention. In this The diagram shows the crank torques over the 152 mm pulling stroke for a previously known crank press and a press according to the invention each other

opposite, where curve a relates to the press of conventional design and curve b relates to the press according to the invention the ram is in the area of the 152 mm stroke position. According to the invention, on the other hand, only a torque of about 13,800 mkp is required to provide the 2001 over the drawing stroke of 152 mm. This reduction in the maximum press torque leads to a reduction in the size of the press and to a crank drive which can be made correspondingly smaller and lighter.

Example III

16 shows a further exemplary embodiment of the invention. In this exemplary embodiment, the plunger 200 is moved by the first lever, ie the link 202 over the plunger movement path F ' Rocker arm 206 with crank 208. The coupling curve is designated 210; it has the main axis V drawn and the minor axis W also drawn. The numbers on the coupling curve correspond to the numbers on the circular arc of the crank 208. The closer the corresponding points are on the coupling curve, the lower the ram speed, since the numbers on the crank circle are the same angle of rotation of a continuously rotating crank. If the distance between the points of the coupling curve increases, the ram speed increases accordingly. The first link 202 has the hinge connection points or the axes a 1 and a 1, which correspond to the points and C i g. 5 to 10 correspond. The coupling lever 204 is connected between the hinge axes as and at , which correspond to the points a and cent. The fixed axis a ₂ is the center O of the crank 208, while the fixed axis as corresponds to the point D about which the rocker arm 206 swings. In this embodiment, the following length dimensions are provided:

It should be mentioned that the coupling curve according to FIG. 16 has essentially the same properties like that of the exemplary embodiments I and It. Also the basic arrangement of the individual levers »and Articulated links correspond to those of exemplary embodiments I and II.

FIG. 17 shows a mathematical relationship with which the individual points on the coupling curve 220 are determined as a function of two right-angled axes, the origin of which coincides with the center point O of the crank. It is not necessary here into the details of the various

Crank 208 261.4 mm Coupling lever 204 591.8 mm Rocker arm 206 549.2 mm a ₂ a ₅ (OD) 653.9 mm Handlebar 202 1268.5 mm <? 3-a < (ab) 374.4 mm Angle X 18.5 ° a2 - / (intersection of Line find a line that perpendicular to the line a ^ -as runs through the axis a ₂ ) 2263 mm

15 16

enter into mathematical relationships, the crank see derivation result for the determination of the

is with Γ ,, the coupling lever with ri, the rocker arm with individual points of the coupling curve 220 the two

η and the distance between the two fixed equations below;

Axes O and C denoted by Γ4 The fourth axis is _v _ _ r> r \ ca _i_ nncna .im / i \

the axis D, over which the coupling with the (not -, ^Λ ° ~ ^r '^{LL>i> ö) + e {Jüii} ^ ² + ^ψ > W

The first lever shown) is made from the mathematical Yd = η SIN Θ, + e SIN (θ ₂ + 5 ·). (2)

In addition 9 sheets of drawings

Claims (1)

Claims; 1, ZiehpK'se with the press ram guided in a straight line in the press frame, which is driven by a drive crank via a Gelsnkgetriebe, which has a link with its one end on the ram at point E , the other end of which is articulated at coupling point C with a coupling lever, which, in turn, is articulated in point a on the driving crank with the radius rotating around the center O , and with a rocker arm, which is articulated with one end in connection point D on the press frame and with its other end in point b on the coupling lever, which is in Distance from point a and coupling point C , the coupling point C describes a coupling curve which is defined as follows: