FR2659577A1 - DEEP HYDROELASTIC STAMPING DEVICE. - Google Patents

Abstract

Hydroelastic deep drawing device, comprising a hydraulic device with multi-point control, a pressure cylinder (10) with interlocking remote holding rod (16), combined at each target point, and hydraulic control circuits (26 , 27) can be connected to each pressure cylinder. The punch (5) and / or the blank holder plate (12) can each be activated by a hydraulic circuit (26, 27), by means of the remote holding rods (16) fitted onto the pistons (11). At least one differential cylinder piston rod (3) can be activated by the punch (5), and / or differential cylinder piston rods of the blank holder plate (12) can be activated for control of the punch (5) and the plate (12). An external measuring system is used to control the acceleration and deceleration paths, and set stroke positions.

Description

DEEP HYDROELASTIC STAMPING DEVICE

  The invention relates to a deep hydroelastic deep drawing device for stamping presses for the stamping of stamped sheet metal parts, comprising a blank plate applied by the tool against hydraulic pressure cylinders, by means of distance-holding rods, and a stamping punch, movable and guided in the stamping direction, which rests on at least one piston guided in a cylinder and capable of

  be stressed by hydraulic fluid.

  The tooling technique includes, for forming metals for the production of stamped sheet metal parts, the use of

  distance-holding rods to provide support for the clamp plates

  blank These distance holding rods are pressure rods between the blank holder plate and the blank holding pad They constitute an essential component of the deep drawing tool considered, that is to say that the length and the number of holding rods at

  distance are conditioned by the tool.

  It has been found that these distance-holding rods have the disadvantage of wearing out, so that, in the case of a system with rigid blank holder, it can thus be established, in an uncontrolled manner, unevenness of clamping force of the sheet during operation, which results in the formation of uncontrolled folds in the shaped part. This effect can be avoided with

  elastic tightening, by interposition of a rubber plate.

  By German patent DE-PS 30 22 844, a deep drawing device is already known on tools or presses for stamping sheet metal parts, which, for the support of a blank holder plate, has a clamp holder blank consisting of several pressure cylinders and of pistons which are stressed by pressurized fluid and are guided with the possibility of axial displacement in these cylinders, this device being equipped with another cushion receiving a stamping punch guided with the possibility of movement in the drawing direction, its pressure cylinders being connected by flow paths to the pressure cylinders of the blank holder cushion serving as support for the blank holder and, during drawing, being stressed by fluid pressure discharged from these pressure cylinders. An important fact inherent in this deep drawing device is that, during the descent of the stamping die actuated by a press slide, pressure fluid flowing out of the pressure cylinders of the greenhouse blank cushion serve as a support of the blank holder arrives via conduits in the pressure cylinders of the other cushion on which the stamping punch is received with the possibility of vertical movement, and biases the pistons guided in the pressure cylinders of this cushion, said pistons driving for their part in the direction of stamping, during stamping, the punch against the direction of movement of the stamping die and the blank holder plate This direct fluid connection between the pressure cylinders of the field action of the blank holding plates and the pressure cylinders of the punch's field of action is intended to constitute this

  which is called a pressure balance.

  The disadvantages of mechanical distance rods

  could have been avoided with a known deep drawing device.

  The following drawbacks have appeared with this deep drawing device: The forces which are established are not reproducible since there is a dependence between them and the drawing speed, this due to differences in resistance to flow, i.e. the device is not suitable for process control by

computer program.

  Between the beginning and the end of the deep drawing process, the evolution of the forces during sheet metal forming is more or less parabolic, especially in the case of flat stamped parts or parts, or in the case of parts with geometry. complicated, it is however imperative to apply at the beginning of the clamping forces higher blanks in particular areas of action of the blank holder. To compensate for this drawback, a pressure control valve has been adopted, according to German patent DE-OS 33 33 687, in order to be able to establish, via this pressure control valve, different

  pressures in the hydraulic oil flow path between clamps

  blank and stamping punch, for example at the start or even in

  principle, on the whole of the stamping.

  In practice, this command has the following disadvantages: a) if there are different pressure conditions in the fields of action of the blank holder and the punch, the oil is compressed differently; b) the pressure control valve has a leakage oil consumption; c) conditions a) and b) above have the effect that no reproducible process or production process can be obtained, that is to say an exact process control is impossible; d) with the high number of pressure cylinders required (100 and more), the expense for the separate control of each individual pressure cylinder, each time by a valve, would be

far too expensive.

  In the case of the two German patents, the fluid connection is also generally affected by a drawback: the stroke of the stamping punch cannot be controlled in a strictly reproducible manner, due to leaks and the

compressibility of oil.

  The object of the invention is to produce, while avoiding the aforementioned drawbacks, a hydroelastic deep drawing device, with computer-assisted process control, in which the pressure cylinders arranged in accordance with the configuration of the holes and the holding rods remotely supported by it, for the field of action of the blank holder plate and the field of action of the stamping punch, are activated in correspondence with

  the geometry of the shape of the part.

  According to the invention, this object is achieved a) by the fact that there is provided a hydraulic stamping apparatus with multi-point control corresponding to the geometry of the shape of the part, a pressure cylinder with holding rod nestable distance being conjugated to each target point, several hydraulic control circuits can be connected to each pressure cylinder by rotation of the envelope thereof;

  b) by the fact that the stamping punch and / or the clamping plate

  blank can each be activated by a hydraulic control circuit, in correspondence with the field of action corresponding to the part and with the field of action of the blank holder plate, by means of the remote-holding rods fitted onto the pistons of the pressure cylinders; and c) by the fact that at least one differential cylinder piston rod can be activated by the stamping punch and / or at least two differential cylinder piston rods from the clamp plate can be activated in control circuits main cylinders, for hydraulic control of the blank holder plate and the stamping punch, and each stroke position can be controlled according to the requirements of the tooling, by means of an external stroke measurement system, to what is the acceleration course and the course of

  deceleration as well as set stroke positions.

  The arrangements and characteristics of the invention allow

  in particular to reconstruct the operating advantages of a greenhouse system

  blank-cushion having the elasticity of a rubber, that with mutually connected hydraulic cylinders, communicating, for the fields of action of the blank holder plate and the stamping punch, however with the advantage and the possibility of computer-assisted process control The solution provided by the invention allows the activation of a large number of hydraulic cylinders in a very narrow space, with a computer-assisted process, that is to say with repeatability at the same with the same program, without each cylinder

  individual must be fitted with valves ordered separately.

  With the main cylinder control circuits by differential piston-cylinder assemblies according to the invention, it is possible to obtain a synchronous control of the blank holder plate during active stamping, an operation approximately parallel with the slide nose can be controlled for moving the blank holder plate,

  so that the "deep drawing" process takes place without shock.

  If this is not so, the impact shock of the nose on the clamping plate

  blank, in the case of large presses and large tools, leads in particular to surface marks on the stamped part, marks which are also called stamping projections or drive edges. Depending on the requirements of the tool, the stroke can also be controlled with position regulation and a parallel return of the blank holder plate can be obtained after the deep drawing operation. The return stroke can then be carried out at high speed, according to a previously programmed speed profile (acceleration and

  deceleration) for clearing or undressing the stamped part.

  It is therefore advantageous for the main cylinder control circuits to be controlled by hydraulic servo-control, with great precision and at low cost, by relatively small oil volumes, for rapid movements The numerous rods for maintaining distance which are actuated hydraulically during the stroke movement can follow more economically, by being controlled with a slower speed, via relatively small hydraulic straight sections. As a result, it is therefore possible to operate with small straight sections for the hydraulic cylinders and with small valves, which further implies lower flow resistances and consequently less energy loss From the possibility of using relatively smaller straight sections of cylinder, for the deep drawing device according to the invention , there results another advantage, namely that the configuration of holes is carried out with a grid field of less than 100 mm, that is to say that in addition we thus come close to the ideal of a

  rubber elastic stamping system.

  The deep drawing device according to the invention also offers the possibility of also using, on this hydraulic deep drawing apparatus, universally and without modification, existing tools used until now for rods or punches of mechanical stamping, the very great possibility of incorporation in hydraulic servo-control processes and the use of different process stages, for example switching of normal 1.5 displacers, deep drawing reverse stamping, and therefore offers

  a wide range of applications, particularly advantageous.

  The possibilities of incorporating into processes the process for controlling the deep drawing operation according to the invention are particularly significant also for guaranteeing the quality of the stamped part to be produced. The disturbing influences, such as for example tilting of the nose of press or tool parallelism defects, can be effectively compensated by the hydraulic controls indicated, for example preventively to avoid

fold formation.

  Among the different possible embodiments, the invention provides in particular: that the pressure cylinders and / or the differential cylinders are mounted in correspondence with the configuration of holes, vertically and close to one another, on the base plate, to constitute a cylinder plate, and, each time by means of quadrangular flanges which are applied to the upper front surface of the cylinder envelopes, are fixed to the base plate by means of bolts; that, in order to extend or narrow the fields of action of the blank plate and the stamping punch, the pressure cylinders can be connected, by rotation of their envelope, either to the control circuit of the blank plate, either to the stamping punch control circuit; that, for a stamping with one or more punches, at least one differential cylinder is provided for each stamping punch, hydraulically controlled associated with the main cylinder control system; that the parallel retreat of the blank holder plate towards the upper initial position, after stamping, is carried out by controlling the differential cylinders from the main cylinder control circuit for the blank holder plate, the recoil stroke being performed at high speed according to a preprogrammed speed profile (acceleration and deceleration), in order to strip the piece while sparing it and to minimize the impact of the nose on the blank holder plate, and being controlled during a release movement with displacement almost in synchronism with the nose; that the pressure cylinders of the field of action of the blank plate, for the control circuit of the blank plate, and the pressure cylinders of the field of action of the stamping punch, for the control circuit of the stamping punch, operate each time separately, but are nevertheless in mutual communication; that the piston rods of the differential cylinders are respectively provided with a coupling system by conjugation of shapes, for coupling to the blank holder plate and, respectively, to the stamping punch on the tool side; that the distance holding rods have a collar at one end; that the upper face of the pressure cylinders is provided with a recess for the support of the distance-holding rods, the diameter of the recess being made larger than the diameter of the distance-maintaining rods; that the unused openings of the configuration of holes in the removable tool plate or in the cylinders themselves can be covered by closing caps with bayonet type fixing or by screwing; that the removable tool holder plate is arranged in the press so as to be able to be raised and lowered, and to be able to be removed in the raised position by movement on rails; that, to receive the collar of the distance-holding rods, countersinks corresponding to the configuration of holes are provided in the removable tool-holder plate; that each pressure cylinder is produced, in correspondence with the configuration of holes, as a differential piston-cylinder arrangement, and by the fact that, for this variant, instead of the piston rod, use retention rods are used remotely made shorter, these differential pistons being able to be stopped by the fact that, when the removable tool-holder plate is released, the distance-holding rods and the tool-holder plate removable in the press are mechanically locked to the plate cylinders; that the pistons include dirt scrapers, which are applied against the walls of the bores of the pressure cylinders; that the pressure cylinders and the differential cylinders are formed with the same dimensioning, for interchangeability according to the configuration of holes; that, to close the pressure cylinders and / or the differential cylinders, plug sockets with closing caps are provided on the cylinder plate, these sockets projecting for this purpose, by an external thread, out of the plane of the plate to cylinders, and the openings of the removable tool holder plate having counterbores corresponding to their lower end, for receiving the plug sockets with closing caps; that, to close the removable tool-holder plate and / or to extend the distance-holding rods, a special rod is provided which is produced with two bayonet-type pins, which serve on the one hand as a collar for the retention in counterbores and, on the other hand, by bayonet type locking in means

  matching adapter in the underside of the holder plate

  removable tool, used to stop the distance holding rods;

  that, to be able to be retracted and retracted, the plate

  removable tool is provided with T-slides arranged on its underside, which can be engaged in or released from T-slots

  corresponding to the cylinder plate.

  The characteristics and advantages of the invention will become apparent

  more fully in the following description presented as

  non-limitative example with reference to the accompanying drawings, the figures of which represent: FIG. 1a, schematically, a deep drawing press in the open position and in the closed working position; Figure lb, the stamping press according to Figure la, without nose, with removable tool holder plate;

  Figure 2, the hole pattern for the holder plate

  removable tool and for the cylinder plate, with combined hydraulic control circuits; Figure 3, a pressure cylinder with distance holding rod; FIG. 4 a, a pressure cylinder with connection to the control circuit of the blank holder plate; FIG. 4 b, the control circuit of the blank holder plate according to FIG. 4 a, angularly displaced, with connection to the control circuit of the stamping punch; Figure 4c, a pressure cylinder with closure cap; and Figure 4 d, the assembly of the removable tool holder plate to

the cylinder plate.

  The figure shows the press with the deep drawing device, & left in the open position and right in the closed working position On the upper crosspiece with nose 2 is mounted the removable upper tool holder plate with the stamping die part 4 On the lower removable tool-holder plate 6 is arranged the stamping punch 5 which, in cooperation with the part

  matrix 4, causes the shaping of the part 7.

  To carry out deep hydroelastic stamping with several hydraulic control circuits, the pressure cylinders and / or the differential cylinders 14 are mounted in accordance with the configuration of holes 18 according to FIG. 2, vertically and close to each other, on the base plate 9, to constitute a cylinder plate 8, and, are fixed each time by means of quadrangular flanges (not shown> which apply to the upper front surface of the casings or cylinder liners, are fixed to the base plate 9 by means of bolts To each target point 20 is assigned, in correspondence with the shape geometry of the part 7, a pressure cylinder with interlocking distance rod 16, and to each pressure cylinder 10 can be connected, by rotation 24 of its casing, several hydraulic control circuits 26 and 27, and the stamping punch 5 and / or the blank holder plate 12 can ent each be activated by a hydraulic control circuit 26 and 27 in correspondence with the field 21 of action on the workpiece and the field of action 22 of the blank holder plate, by means of the distance holding rods 16 fitted onto the pistons 1 i of the pressure cylinders In addition, by means of differential cylinders 14 and pistons 35, at least one differential cylinder piston rod 3 can be activated by the stamping punch 5 and / or at at least two differential cylinder piston rods 3 of the blank plate 12 can be activated in main cylinder control circuits, 15 and 25, for hydraulic control of the blank plate 12 and the stamping punch, and each stroke position can be controlled according to the requirements of the tool, by means of an external stroke measurement system, 23, with regard to the acceleration stroke and the

  deceleration stroke as well as set stroke positions.

  Figures 2, 4 a and 4 b also show how, for

  extend or restrict the fields of action 21 and 22 of the greenhouse plate

  blank 12 and the stamping punch 5, the pressure cylinders 10 can be connected, by rotation 24 of their envelopes, either to the circuit 26 for controlling the blank holder plate, or to the circuit 27 for controlling the stamping punch The individual hydraulic circuits are produced by holes in the base plate 9, as a distributor system for the hydraulic fluid, the pressure cylinders 10 of the field of action 22 of the blank plate, for the control circuit 26 of the blank holder plate and the pressure cylinders 10 of the field of action 21 of the stamping punch, for the control circuit 27 of the stamping punch, being supplied each time separately, but nevertheless being each time mutual communication The unnecessary pressure cylinders 10 are, as shown in FIG. 1 a, inactive by the absence of distance holding rods 16, the openings 30 of the removable tool-holder plate 6 remaining closed by shutter caps 19 The shutter caps 19 have an external thread for this and are

  screwed into an internal thread of the countersink 13.

  FIG. 1b, shows how the distance holding rods 16 with the removable tool-holder plate 6 are released from the connection with the pistons of the pressure cylinders 11, by lifting by means of a piston-pressure cylinder arrangement 42, and how the piston rods 3 act on the blank plate 12

  as well as on the stamping punch 5 By removing the holder plate

  removable tool 6 from press 1, a second removable tool plate can be introduced with new equipment for holding & distance rods, or the first tool plate is equipped with a field of action 21 (equivalent to the field of the stamping punch) corresponding to a new part 7, by engagement and retention, in

  a counterbore 13, distance holding rods 16 provided with a collar 32.

  A tandem execution with a translating table function is also possible During operation, there is always a removable tool plate 6 in the stamping press 1, and the 1 o second is outside the press 1, so to carry out outside the press, in preparation for a change of tool and

  production, mounting the new tool on this tool holder plate 6.

  The control of the differential piston-cylinder arrangement 14 and 35 is carried out, for the blank holder plate 12, from the main cylinder control circuit 25 and, for the stamping punch 5, from the main cylinder control 15, the two pilot circuits can also be supplied each time separately, but nevertheless being in communication each time one

with the other.

  The upper face of the pressure cylinders 10 according to FIG. 3 is arranged with a recess 31 for the support of the distance holding rods 16, the diameter of the recess 31 being made larger than the diameter of the holding rods remotely 16 With this configuration, when the tool is changed, there can certainly be a drop of dirt in the recess 31, but not in the pressure cylinder 10 This is in particular impossible if the pistons 11 are provided with scrapers of stains 34, which are applied against the wall of the bore 33 of the cylinder If necessary, any stains which have fallen into the recess 31 can be removed simply with a vacuum cleaner

to dust.

  The unused openings 30 of the configuration of holes 18 in the removable tool-holder plate 6 or in the cylinders themselves can, according to FIG. 4 c, be masked by closure caps 19 with fixing of the bayonet or screw type A To this end, it is provided, for example in the cylinders 14, closure sleeves 29 which, by an external thread 39, protrude outside the plane of the cylinder plate To receive the closure sleeves 29 with closing caps 19 in the removable tool holder plate 6, the openings 30 of this tool holder plate 6 are provided with corresponding counterbores 40 at their lower end. According to FIG. 4 d, all the pressure cylinders are produced, in correspondence with the configuration of holes 18, as a differential piston-cylinder arrangement 14, 35, and, for this variant, instead of the rod of piston 3, distance holding rods 17 whose execution is shorter, with the possibility of stopping these differential pistons 35, the remote holding rods 17 being stopped on the removable tool-holder plate 6, and the plate removable tool holder 6 being mechanically locked with

the cylinder plate 8.

  To close the removable tool-holder plate 6 and / or to extend the distance-holding rods 17, a rod is provided.

  special 36 which is produced with two nipples of the bayonet type 37.

  On the one hand, the nipples of the bayonet type 37 are then used as a collar for engagement with retention in the counterbores 13 of the removable tool holder plate 6, in which case the special rod 36 serves as an extension of the rods. holding at a distance 17 On the other hand, the special rod 36 ′ is introduced in the inverted position with the bayonet stud 37 in corresponding longitudinal grooves (not shown) in the holes 30 and, by rotation, is locked in recesses 38 in the underside of the tool plate

  removable 6, in order to stop the distance holding rods 17.

  The locking of the removable tool-holder plate 6 on the cylinder plate 8 is effected by T-slides, 28, which are made so that they can be introduced into corresponding T-grooves, 43, of the cylinder plate 8 To this end, the T-slides 28 are fixed on the underside of the removable tool plate 6 The hydraulic circuit 41 makes it possible to bring the

  pistons 11 and 35 of the pressure cylinders.

Claims (15)

  1 Hydroelastic deep drawing device for stamping presses for stamping sheet metal stamped parts, comprising a blank holder plate applied by the tool against hydraulic pressure cylinders, by means of distance-holding rods, and a stamping punch, movable and guided in the direction of stamping, which bears on at least one piston guided in a cylinder and capable of being stressed by hydraulic fluid 1 O, characterized a) in that it there is provided a multi-point hydraulic stamping device in correspondence with the geometry of the shape of the part (7), a pressure cylinder (10) with embossable distance holding rod (16) being conjugated at each point target <20), several hydraulic control circuits (26, 27) which can be connected to each pressure cylinder (10) by rotation (24) of the envelope thereof; b) by the fact that the stamping punch (5) and / or the blank holder plate (12) can each be activated by a hydraulic control circuit (26, 27), in correspondence with the field of action ( 21) corresponding to the part and with the field of action (22) of the blank holder plate, by means of the distance holding rods (16) fitted on the pistons (11) of the pressure cylinders; and c) by the fact that at least one differential cylinder piston rod (3) can be activated by the stamping punch (5) and / or at least two differential cylinder piston rods (3) of the plate blank holder <12) can be activated in main cylinder control circuits (15, 25), for hydraulic control of the blank holder plate <12) and the stamping punch (5), and each position of stroke can be controlled according to the requirements of the tooling, by means of an external stroke measurement system (23), with regard to the acceleration path and the deceleration path as well as 1 5 stroke positions set.   2 Stamping device according to claim 1, characterized in that the pressure cylinders (10) and / or the differential cylinders (14) are mounted in correspondence with the configuration of holes (18), vertically and close to each other. others, on the base plate (9), to constitute a cylinder plate (8), and, each time by means of quadrangular flanges which are applied to the upper front surface of the envelopes of   cylinders, are fixed to the base plate (9) by means of bolts.   3 stamping device according to claims 1 and 2,   characterized in that, to extend or narrow the fields of action (21, 22) of the blank holder plate (12) and the stamping punch (5), the pressure cylinders (10) can be connected, by rotation (24) of their casing, either to the control circuit (26) of the blank holder plate, or to the control circuit (27) stamping punch.   4 Stamping device according to any one of   Claims 1 to 3, characterized in that, for stamping   with one or more punches (5), at least one differential cylinder (14) is provided for each stamping punch (5), on order   hydraulics associated with the main cylinder control system (15>.   Stamping device according to any one of   Claims 1 to 4, characterized in that the parallel recoil of   the blank plate (12) to the upper initial position, after stamping, is carried out by controlling the differential cylinders (24) from the main cylinder control circuit (25) for the blank plate (12 >, the reversing stroke being carried out at high speed according to a preprogrammed speed profile (acceleration and deceleration), in order to strip the piece while sparing it and to minimize the impact of the nose (2) on the blank plate (12 ), and being controlled during a disengagement movement with displacement almost in synchronism with the nose (2).   6 Stamping device according to any one of   Claims 1 to 5, characterized in that the cylinders of   pressure (10) of the field of action (22) of the holding plate, for the control circuit (26) of the holding plate, and the pressure cylinders (10) of the field of action (21) of the stamping punch, for the control circuit (27) of the stamping punch, operate at each   times separately, but are nevertheless in mutual communication.   7 Stamping device according to any one of   Claims 1 to 6, characterized in that the piston rods   (3) differential cylinders (14) are respectively provided with a coupling system by conjugation of shapes, for coupling to the blank holder plate (12) and, respectively, to the stamping punch (5) tool side.   8 Stamping device according to any one of   Claims 1 to 7, characterized in that the holding rods   remote (16) have a collar (32) at one end.   9 Stamping device according to any one of   Claims 1 to 8, characterized in that the upper face   pressure cylinders (10) is provided with a recess (31) for the support of the distance holding rods (16), the diameter of the recess (31) being made larger than the diameter of the rods of remote maintenance (16).   Stamping device according to any one of   Claims 1 to 9, characterized in that the openings   unused (30) configuration of holes (18) in the removable tool plate (6) or in the cylinders themselves can be covered by closure caps (19) with fixing of the type bayonet or by screwing.   11 Stamping device according to any one of   Claims 1 to 10, characterized in that the tool plate   removable (6) is arranged in the press (1) so that it can be raised and lowered, and can be removed in the raised position by movement on rails. 12 Stamping device according to any one of   Claims 1 to 11, characterized in that, to receive the   collar (32) of the distance holding rods (16), counterbores (13) corresponding to the configuration of holes (18) are provided in the removable tool plate <6).   13 Stamping device according to any one of   Claims 1 to 7, 10 and 12, characterized in that each   pressure cylinder is made, in correspondence with the configuration of holes (18), as a differential piston-cylinder arrangement (14, 35), and by the fact that, for this variant, instead of the rod is used piston (3) of the distance holding rods (17) made shorter, these differential pistons <35) being able to be stopped by the fact that, when the removable tool-holder plate (6) is released, the holding rods distance (17) and the removable tool plate (6) in the press (1) are mechanically   locked to the cylinder plate (8).   14 Stamping device according to any one of   Claims 1 to 13, characterized in that the pistons (11)   have dirt scrapers (34) which are applied against   the walls of the bores (33) of the pressure cylinders (10).   15 Stamping device according to any one of   Claims 1 to 14, characterized in that the cylinders of   pressure (10) and the differential cylinders (14) are made with the same dimensioning, for interchangeability according to the configuration of holes (18).   16 Stamping device according to any one of   Claims 1 to 15, characterized in that, in order to close the   pressure cylinders and / or differential cylinders (10, 14), plug sockets (29) with closing caps (19) are provided on the cylinder plate (8), these sockets overflowing for this purpose, by a thread outside (39), outside the plane of the plate & cylinders, and the openings (30) of the removable tool holder plate (6) having corresponding counterbores (40) at their lower end, for   receive the plug sockets <29) with closing caps (19).   17 Stamping device according to any one of   Claims 1 to 7, 10, 12 and 13, characterized in that, for   close the removable tool holder plate (6) and / or to extend the distance-holding rods (17), a special rod (36) is provided which is produced with two bayonet-type pins (37), which serve on the one hand, a collar for retaining in the counterbores (13) and, on the other hand, by bayonet type locking in corresponding adaptation means (38) in the underside of the removable tool holder plate (6 ), are used to stop the holding rods at distance (17).   18 Stamping device according to any one of   claims 1, 12, 13, 14, 15, 16, 17, characterized in that,   to be retractable and retractable, the removable tool holder plate (6) is provided with T-slides (28) arranged on its underside, which can be engaged in or released from the T-grooves   corresponding to the cylinder plate (8).