Abstract:
A device for the production and/or machining of parts, in particular for the production of stampings, by at least one die which is capable of being put under pressure and/or force, and which has at least one plate and one die element, the die element being supported in the plate against pressure elements via a resilient element.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a device for the production and/or machining of parts, in particular for the production of stampings, by means of at least one die which is capable of being put under pressure and/or force, and which has at least one plate and one die element, the die element being supported in the plate against pressure elements via a resilient element. 
   The present invention refers to all machines having a die by means of which parts are to be produced or machined under pressure. For example, the machining machines may be deep-drawing devices or the like. Particular reference is made, however, to stamping machines, in which stampings are produced in a die consisting of an upper and of a lower die part between which a material strip is clamped. Appropriate cutting or forming elements then press onto the material and separate it out or form it. 
   A subtype of stamping is fine blanking. A corresponding fine-blanking device is shown, for example, in DE 35 76 129 A1. A fine-blanking die is found in DE 197 51 238 A1. 
   Both EP-A-0 418 779 and Patent Abstracts of Japan BD 007 No. 020 (M-188), 26 Jan. 1983 (1983 Jan. 26)-&amp;JP57 175027 A (TAKESHI OOSHIMA), 27 Oct. 1982 (1982 Oct. 27) disclose in each case a cutting or stamping die, in which a die element is supported against a pressure element via resilient elements and is thereby held with a clearance from a die plate. 
   Problems arise, inter alia, with regard to the introduction of forces into the die, that is to say the arrangement of the force-transmitting elements is greatly restricted. Conventionally, the dies are nowadays constructed as follows: 
   The knife-edged ring or pressure pad pressure cylinders are arranged centrically in the press body or ram. The transmission force from the pressure cylinder to the die takes place via what is known as an insert ring or a die plate which are arranged centrally above the pressure cylinder. The disadvantages of this central pressure cylinder arrangement is that force transmission cannot be co-ordinated with the die requirements. Furthermore, there is no possibility of dividing the work steps into a plurality of work steps independent of one another when different pressure intensities or strokes are required. This refers both to the number of force-transmitting elements and to their size and position. This rigid arrangement of the pressure cylinders results in the tipping or counting of the pressure plate when dies with eccentric load are used. In order to avoid this weak point, displaceable pressure pads have also already been used, but these have the serious disadvantage that the required outlay in terms of setting up is unacceptable, and the press body and the press ram are correspondingly weakened in their structure due to the large orifices, and the pad dimensions cannot be varied as desired. 
   The object on which the present invention is based is to develop a method and a device of the type mentioned above, which allow a free and flexible arrangement and activation of the force-transmitting elements, so that stampings of any desired size and geometry can ultimately be manufactured. 
   SUMMARY OF THE INVENTION 
   The foregoing object is achieved wherein at least one crossbridge is arranged between the die element and at least two pressure bolts and is seated in the die displaceably opposite to the main pressure direction of the press. 
   The basic idea of the present invention is an array of force-transmitting elements, in which these may be executed in any desired number and in a variable arrangement and transmission area. The forces themselves which are transmitted by the force-transmitting elements may be generated hydraulically, pneumatically, by spring force, mechanically or electromotively. The force-transmitting elements can be adapted in their size and number correspondingly to the respective die concept. The individual force-transmitting elements can be both force-dependent and travel-dependent independently of one another and can be controlled and/or regulated according to the requirements of the die. 
   A corresponding device is composed of a plurality of individual force-transmitting machine elements (cylinders, springs) which are arranged so as to be distributed in any desired grid over the entire platen surface or ram surface of the press. The individual elements/stations can be controlled independently of one another or in any desired arrangement in a pressure-dependent and/or travel-dependent and/or force-dependent manner. The individual stations/elements can be connected to one another in any desired number and arrangement via bridge battens of varying length or moldings of any desired shape in the die change plates or in the die. A plurality of force transmission arrays independent of one another can thus be provided in a different length/extent and with a different force. 
   In order to cover each pressure bolt position of the individual die stages (modules), corresponding crossbridge battens (or moldings) are arranged in the die. These crossbridges are designed according to the individual die stages and are an integral part of the die. 
   By virtue of this construction, the following points can be covered:
         any desired number of force transmission arrays   different forces of the individual transmission elements   any desired extent/array size of the force transmission elements due to their coupling by means of the bridges described   different travels/stroke lengths of the individual force transmission elements   virtually any desired number and position of pressure bolts (pressure bolts=force transmission elements in the die)   full-area die support.       

   The method according to the invention and the corresponding device have the great advantage that
         flexibility in the construction of a (fine-blanking) die can be increased considerably. The force-transmitting elements can be arranged entirely freely in terms of their position according to the requirements arising from the stamping geometry. This arbitrary arrangement allows an optimal configuration of the process steps and of the die.   the capacity to produce fine stampings is no longer limited by the geometric restrictions in the die construction or reduced by restrictions in the arrangement of the process steps in the die.   the die construction can become simpler. A plurality of process steps which are partly integrated into a die stage in present-day progressive dies can be corrected. As a result, process reliability can be increased, the outlay for co-ordinating the die elements can be reduced and setting-up times can be shortened.   contrary to nowadays, the die is supported over the entire bearing surface and the precision of the parts and the service life of the die are thereby increased.       

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages, features and details of the invention may be gathered from the following description of the preferred exemplary embodiment and with reference to the drawing in which: 
       FIG. 1  shows a partially illustrated cross section through a device according to the invention for the production and/or machining of parts; 
       FIG. 2  shows a partially illustrated cross section through the device according to  FIG. 1 , but rotated through 90°. 
   

   DETAILED DESCRIPTION 
   Of the device P for the production and/or machining of parts,  FIGS. 1 and 2  show a die lower part  1 , a die change plate  2  arranged beneath it and a press platen  3  arranged beneath the die change plate  2 . The die change plate  2  is preferably connected to the press platen  3  via T-strips which engage at least partially into T-grooves. How this takes place is illustrated, for example, in DE 36 62 351 A. 
   A ram  12  and, in this, a pressure force ram  5 , for example a further hydraulic ram, are guided in the press platen  3 . A ring  36  surrounds the pressure force ram  5  in the position of use. 
   In the press platen  3  are arranged a plurality of pressure force rams  5 , above each of which is seated a pressure bolt  6  which is guided and held in the die change plate  2 . Between a head  7  on the pressure bolt  6  and a shoulder  8  in the die change plate  2  is located a supporting spring  9  which holds the pressure bolt  6  in a supported position. In this supported position, the pressure bolts  6  support a crossbridge  10 , so that a free space  11  is located between the crossbridge and the die change plate  2  due to the formation of a clearance a. This supporting position of the pressure bolt  6  allows a frictionless change of the die change plate  2  together with the crossbridge  10 , since the pressure bolts  6  do not hang out of the die change plate  2  downward. 
   The crossbridge  10  is equipped with a sprung ball thrust screw  13 . This ball thrust screw  13  latches into a groove  14  of the change plate  2  and thus fixes the crossbridge  10 . 
   The length of the crossbridges  10  are designed according to the die requirements such that they cover two or more pressure bolts  6 . 
   On the crossbridge  10  lies a frame  15 . In this frame  15  can be seen a compartment  16  in which a pressure bolt bridge  17  is guided displaceably. The pressure bolt bridge  17  is supported against the crossbridge  10  via a bearing mushroom  18 , the bearing mushroom  18  being connected to the pressure bolt bridge  17  by means of a screw bolt  19 . The bearing mushroom  18  has the effect that the pressure bolt bridge  17  likewise maintains a clearance a from the surface of the change plate  2 . This clearance also corresponds to the clearance a of the crossbridge  10  in the free space  11  of the change plate  2 . It defines the maximum pressure pad stroke. 
   The shape of the compartment  16  and of the pressure bolt bridge  17  is governed by the respective die requirements. In the same way as the crossbridge, the pressure bolt bridge also need not be a straight molding, but, instead, moldings of any desired shape may be envisaged, for example oval, round or at an angle to one another. The compartments  16  and free spaces  11  then also have corresponding configurations. 
   Furthermore, in  FIG. 1 , a recuperator  20  can be seen for the pressure bolt bridge  17 . This recuperator has a screw bolt  21  which is screwed into the pressure bolt bridge  17 . The head  22  is supported via a helical spring  24  against a lower step  25  of this stepped bore  23 . 
   By virtue of this embodiment, the pressure bolt bridge  17  together with the bearing mushrooms  18  is drawn upward, and the lower edge of the bearing mushrooms  18  is flush with the lower edge of the frame  15  or of the die lower part  1 . As a result, the die lower part  1  can easily be pushed out and in for the die change. 
   A die element  26 , which is an ejector in the present exemplary embodiment, presses onto the pressure bolt bridge  17  via a bolt  28 . Of this ejector, an ejector ring  27  is shown which lies on a pressure bolt  28 . The ejector ring  27  can be pressed against the pressure bolt bridge  17  via this pressure bolt  28 . It is pressed back into the initial position by means of a helical spring  29 . 
   The pressure bolt  28  passes through a baseplate  30  which lies on the frame  15 . This baseplate  30  is connected to a die proper  32  via height compensation  31 , this taking place by means of a corresponding screw bolt  33 . A knife-edged ring  34  for fine blanking can be seen on the die proper  32 . 
   The present invention functions as follows: 
   If, for example, a part is to be stamped out, in particular fine-blanked, from a metal sheet, a fine-blanking device is used, such as is described by way of example in DE 35 76 129 A. The corresponding die consists there of two die halves, to be precise of an upper and of a lower die half, and the device according to the invention may be used in both die halves, but it is also within the scope of the invention for the device according to the invention to be used only in one die part. 
   If, then, a fine-blanking operation is carried out, the two die halves are brought together, the metal sheet, from which the part is to be cut out, being arranged between the two die halves. The die proper  32  co-operates with a counter element, a considerable pressure/force being exerted on the die proper  32  and also on the die element  26 . According to the invention, this pressure/force is transmitted via the height compensation  31  and the baseplate  30  and also via the frame  15  to the crossbridge  10  which, in turn, absorb forces (for example, also a tipping force or unequal forces) in that the pressure bolts  6  of the pressure force ram  5  yield correspondingly. This yielding takes place in the region of the free space  11  due to a reduction in the clearance a between the crossbridge  10  and die change plate  2 . 
   If unequal forces are transmitted to the die element  26 , a transfer of these forces takes place here via the pressure bolt bridge  17  and the bearing mushroom  18  to the crossbridge  10  and from the latter, in turn, to the pressure force element  5  via the pressure bolt  6 . An ideal compensation of uneven forces thus takes place. 
   The number and arrangement of the pressure bolt  6  and of the pressure force ram  5  may be assigned to the individual die workstations via the crossbridge  10 . The pressure bolt bridges  17  can then be adapted to the requirements of each workstation. 
   A particular configuration is additionally provided for the pressure force ram  5 . This is preferably received in a hydraulic cylinder in the ram  12 . For example, three pistons are seated on it, each piston possessing a specific pressure space which can be acted upon with a pressure medium. As a result, a force on the pressure force ram  5  is increased substantially and counteracts the penetration of the pressure bolt  6 .