EP2008799A1 - Die cutting press - Google Patents

Abstract

The punching press comprises clamping plates (27) and a press ram (1). The press ram lies opposite to an upper side of the clamping plate and operates towards the clamping plate. The press ram moves up and down through four tension columns (2) by a crank drive. The crank drive is arranged below a belt movement plane (X) of the punching press.

Description

The present invention relates to a stamping press according to the preamble of patent claim 1.

For the industrial production of sophisticated stamping parts punching presses with a arranged below the punching plane and connected via tension columns with the press ram drive mechanism have proven to be particularly suitable because with such punch presses, especially in versions in which the press ram at each of its four outer corners is connected to a tension column, a maximum tilting stiffness both in the direction of passage and at right angles to achieve. As an example of such a press is the punching machine type BSTA 60 from Bruderer AG, CH-Frasnacht, mentioned, from which since 1965 more than 1100 pieces were built. In this punch press each two of the four tension columns are driven by a common crank mechanism by the crank shaft remote end of the connecting rod of the crank mechanism is articulated directly to a yoke rigidly connecting the two tension columns.

In view of the ever-increasing demands on the punching frequency and the punching precision, this machine concept can no longer meet all requirements, especially since a further increase in the maximum punching frequency precludes a disproportionately increasing component load and, associated therewith, corresponding wear or a correspondingly increasing maintenance intensity.

It is therefore the object to provide a multi-stage press available, which does not have the aforementioned disadvantages of the prior art, or at least partially avoids.

This object is achieved by the multi-stage press according to claim 1.

Accordingly, the invention relates to a punch press with a fixed platen and with a top of the platen opposite and working against the platen press ram. For the operation of the punch press the stationary tool part of a punching tool to be operated with the punch press is supported by the top of the platen, while the moving tool part is carried by the press ram. The press ram is driven by tension columns, which preferably serve not only the transmission of the drive forces on the press ram but also the leadership of the press ram, with a arranged below the punch plane drive mechanism such that it performs the required for the punching operation upward and downward movement. For this purpose, the drive mechanism has at least one crankshaft with one or more connecting rods arranged on one or more crankpins of the crankshaft, with which a rotational drive movement provided by a drive motor is converted into an intermittent upward and downward movement for the drive of at least one tension column of the press ram can. Depending on the design, the crankshaft so the drive only serve a train column, the drive of several tension columns or the drive all Zugsäulen the punch press.

According to the invention, in each case the end remote from the crankshaft of each connecting rod is articulated at a first end of a lever or at respective first ends of a plurality of levers, which levers are articulated at their second ends directly or indirectly to the structure of the punch press, for example by means immovably mounted on the housing of the punch press Supporting bolt (directly), or eg via a support assembly attached to the housing of the punch press with a relative to the housing adjustable articulation point for the lever and / or a tab (indirectly). The linkage is such that the one or more levers can be swung back and forth around its second end by rotating the crankshaft through the connecting rod. Further, the lever or the levers are each connected in an area between the first and the second end hingedly connected to at least one tension column of the punch press, such that the tension column can be moved up and down by swinging the respective lever back and forth.

This configuration of the stamping press has the advantage that a division of the ram drive forces results, whereby the bearing load of the crankshaft is significantly reduced, which in turn is beneficial to a long service life of the press (low wear) and high precision even at high punching frequencies.

In a preferred embodiment of the stamping press, the vertical position of the articulation point of the respective lever on the structure of the punch press is adjustable, preferably during operation of the press. This results in the advantage that an adjustment of the ram height is possible, with advantage also during operation.

This setting is preferably carried out in each case by means of a threaded spindle, with advantage in each case by means of a threaded spindle driving servomotor. Such solutions are tried and tested, cost-effective and safe, because form-fitting, and also allow automated adjustment / adjustment of the articulation point via a controller.

Further, it is preferred in both aforementioned embodiments of the punch press that the punch press has a plurality of such levers, at the first ends of which the crank shaft remote end of a connecting rod is articulated and which are each hinged at its second end directly or indirectly to the structure of the punch press, such that the respective lever when rotating the crankshaft through the connecting rod to its second End is pivoted around back and forth, and which are each connected in an area between its first and its second end articulated preferably with exactly one, the respective lever associated tension column of the punch press, such that this tension column when swinging back and forth of the lever upwards - and is moved down. Here, the punch press is designed such that the vertical positions of the articulation points of the second ends of the lever groups or independently adjustable. Such stamping presses have the advantage that the plunger can be kept substantially parallel in an eccentric load by a specifically different setting of the vertical positions of the articulation points of the lever.

In a further preferred embodiment of the stamping press, the lever or the levers are each at the second end via a tab indirectly hinged to the structure of the punch press. This results in a horizontal mobility of the lever with the additional advantage that essentially only vertical forces can be transmitted via this articulation point to the structure, so that a bending stress of the articulation point-forming components is substantially avoided. This is particularly advantageous when the point of articulation is formed by an adjustable support arrangement, e.g. from a threaded spindle with which the vertical position of the articulation point is adjustable.

In yet another preferred embodiment of the stamping press, the lever or the levers are each connected in the region between the first and the second end via a tab with the tension column.

This results in a horizontal mobility with the additional advantage that essentially only vertical forces can be transmitted via this articulation point, so that a significant bending stress of the tension column can be substantially excluded.

In yet another preferred embodiment of the stamping press, there is in each case a guide, by means of which the end remote from the crankshaft of the respective connecting rod is guided vertically, such that its articulation point for the lever or levers is movable exclusively in the vertical direction. This results in a horizontal determination of this articulation point, which simplifies the articulation of two mirror-inverted opposite lever on a common connecting rod.

Accordingly, it is preferred in the aforementioned embodiment that the crankshaft distal end of the respective connecting rod forms a common point of articulation with the first ends of two opposing, seen in crankshaft longitudinal direction mirror image arranged lever, which preferably each seen in the crankshaft longitudinal direction in a mirror image with exactly one, the respective lever associated Zugsäule are connected. This results in the advantage of a compact design and a zwangsssynchronen drive two Zugsäulen.

In yet another preferred embodiment of the stamping press, the at least one crankshaft runs in the longitudinal direction of the punching press, ie in the direction of passage of the same, wherein it is preferred that exactly one crankshaft extending in the longitudinal direction is present for driving all the tension columns. As a result, an inventive punch press can be realized in a simple and cost-effective manner, in which all tension columns are forcibly synchronized.

In yet another preferred embodiment of the punch press this has exactly four tension columns, which are each arranged at the corners of the plunger. In this way, a maximum tilting rigidity of the plunger can be achieved both in the longitudinal direction and transversely thereto.

It is preferred that the punch press has exactly one extending in the longitudinal direction crankshaft for driving all the tension columns and this crankshaft is arranged centrally along the longitudinal axis of the punch press, such that there is a symmetrical arrangement with respect to the tension columns. This results in the advantage of a symmetrical distribution of forces in the entire press arrangement, whereby a maximum parallelism of platen and plunger can be achieved even under load.

In the aforementioned embodiment, it is further preferred that the crankshaft distal end of the respective connecting rod is articulated in a common point of articulation at the first ends of two opposing, seen in the crankshaft longitudinal direction mirror image lever, which is preferably viewed in the crankshaft longitudinal direction in a mirror image with exactly one, associated with the respective lever train column, and that the crankshaft has exactly two crank pins, which are preferably arranged in each case in the region of one end of the crankshaft and at least on the side facing away from the respective shaft end of this crank pin associated, preferably designed as a rolling bearing radial bearing of the crankshaft flanked. Such a structure has the advantage that an arrangement of the crank pin at the longitudinal position of the tension columns is possible, so that any bending moments generated by bearing forces in the press structure in the longitudinal direction can be avoided.

It is further advantageous that the crank pin are each flanked on both sides by a respective crank pin, preferably designed as a rolling bearing radial bearing of the crankshaft, so that an introduction of bending moments in the crankshaft is substantially avoided.

Further, in the two aforementioned embodiments of the punch press, it is preferable that the Crankshaft in the region between the radial bearings, which are each arranged on the side facing away from the shaft end of the respective crank pin, is designed as a hollow shaft. As a result, the rotational moment of inertia of the crankshaft can be kept relatively small, with good rotational rigidity at the same time.

It is further preferred that the crankshaft be constructed, i. composite shaft is formed, in such a way that the part formed as a hollow shaft is formed as a separate component from the crank pin. As a result, a separate production of smaller components is possible and it can be a variety of crankshafts from a few components are formed (modularity), so that can reduce manufacturing and storage costs.

In yet another preferred embodiment of the stamping press, the crankshaft is designed such that the lifting height of its crank pin is adjustable. It is further preferred that the crankshaft has crankpins, which are each formed by an eccentric and a rotatably mounted on this eccentric bushing, such that by turning the eccentric bushing on the eccentric different lifting heights of the crankshaft are adjustable. This results in the advantage of the adjustability of the lifting height.

If the eccentrics and eccentric bushes of the respective crankpins are in certain positions with each other with locking means, preferably with a locking pin, lockable to define a certain stroke height of the crankshaft, then adjustment to specific, precisely defined values is possible in a simple manner.

In the aforementioned embodiment, if the crankshaft is in the region between those radial bearings, which are each arranged on the side facing away from the shaft end of the respective crank pin, designed as a hollow shaft, which is preferred, it is further preferred that the locking means are releasable via a central release mechanism which extends through the interior of the hollow shaft formed as part of the crankshaft extends. This design allows a simple design with easier unlockability and thus easier Umstellbarkeit the machine to other lifting heights.

In yet another preferred embodiment of the stamping press, the crankshaft is mounted in radial bearings, wherein exactly one of the radial bearings of the crankshaft designed as a fixed bearing for receiving the forces acting on the crankshaft axial forces. This results in the advantage that the crankshaft has a defined axial bearing, in contrast to the usual "flying" storage.

In yet another preferred embodiment of the stamping press, the crankshaft is mounted in radial bearings, which are each assigned to one of the crankpins and crankpins are each stored in a separate housing part, which is each connected to a central, the platen bearing or forming housing part, preferably by screwing. As a result, the basic structure of the punch press can be made up of several smaller, modular components, which enables savings in storage and manufacturing costs.

• Fig. 1 einen Querschnitt durch eine erfindungsgemässe Stanzpresse entlang der Linie A-A in Fig. 2;
• Fig. 2 einen Längsschnitt durch eine erfindungsgemässe Stanzpresse entlang der Linie B-B in Fig. 1;
• Fig. 3 eine Draufsicht auf die Stanzpresse aus den Figuren 1 und 2 bei entferntem Pressenstössel;
• Fig. 4 zwei Horizontalschnitte durch eines der beiden Maschinengehäuse der Stanzpresse aus den Figuren 1 bis 3 mit verschiedenen Varianten von Spindelantrieben für die Stösselhöhenverstellung;

Further preferred embodiments of the invention will become apparent from the dependent claims and from the following description with reference to FIGS. Showing:

• Fig. 1 a cross section through an inventive punching press along the line AA in Fig. 2 ;
• Fig. 2 a longitudinal section through an inventive punching press along the line BB in Fig. 1 ;
• Fig. 3 a plan view of the punch press from the FIGS. 1 and 2 with the press ram removed;
• Fig. 4 Two horizontal sections through one of the two machine housing of the punch press from the FIGS. 1 to 3 with different variants of spindle drives for the ram height adjustment;

The basic structure of an inventive punch press is from the FIGS. 1 to 4 which has a cross-section ( Fig. 1 ), a longitudinal section ( Fig. 2 ), Horizontal sections through one of the machine housings ( Fig. 4 ) of the punch press, as well as a plan view of the punch press with the press ram removed ( Fig. 3 ).

As can be seen, the basic structure of the punch press consists of two machine housings 15, 15b, and a cross member 15a with a clamping plate 23, which are connected to each other by means of screws 15d. Above the platen 23, a press ram 1 is arranged, which is rigidly connected to four each arranged at its outer corners tension columns 2. Each two of the tension columns 2 are respectively associated with one of the two machine casings 15, 15b, which also contain the drive mechanism described below for the respective tension columns 2, and are mounted vertically displaceably in guides 3 in these, wherein the guides 3 are installed in guide supports 4, at the same time form parts of the housing cover 4 of the respective machine housing 15, 15b. The two associated with a common machine housing 15, 15b tension columns 2 in the machine housing 15, 15b each rigidly connected via a yoke 5, which in turn is articulated with two tabs 6 via bolts 6a hinged to four levers 7. The press center facing away from the ends of these levers 7 are fixed with tabs 7a on spindle nuts 20, which for adjusting the distance between the plunger 1 and platen 23 with spindles 19 vertically can be moved. The drive of these spindles 19 is based on worm wheels 18, which each take over together with a bearing assembly 17, the storage of the respective spindle 19. In order to prevent co-rotation of the spindle nut 20 during rotational movement of the spindle 19, the spindle nut 20 has an anti-rotation in the lid 20a. The press center facing the ends of the lever 7 are connected by a common connecting rod with a connecting rod 8. The upper end of the connecting rod 8 performs in operation a lifting movement and is guided with two sliders 21 in linear guides 22, such that the connecting rod can perform only a vertical movement. In the lower, large connecting rod bore of the crank pin 9, 10 of the crankshaft 9, 10, 29, which is formed by an eccentric 10 and an eccentric bushing 9. By rotating the eccentric bush 9 relative to the eccentric 10, the resulting total eccentricity of the crank pin 9, 10 can be changed, which corresponds to a change in the stroke of the crankshafts 9, 10, 29 and thus also a changed stroke of the punch press. In the present case, the punch press can be set to a number of well-defined lift heights by different relative angular positions between the eccentric bushing 9 and the eccentric 10 can be fixed positively with a locking pin 32. The locking pin 32 can be unlocked with a release mechanism 31 for Hubwechseln and then rotate the eccentric 10 relative to the eccentric bushing 9, while the latter 9 with a latch 25 which is inserted with a latch piston 26 is temporarily secured against rotation.

The crankshaft 9, 10, 29 consists of the two respective crank pins 9, 10 arranged on the end side thereof and a hollow shaft 29, which connects the crank pins 9, 10 to one another and is protected by a cover (15c). It is with three movable bearings 30 and a fixed bearing 33 in the machine housings 15, 15b stored. The release mechanisms 31 are connected to one another via a coupling shaft 28 running in the center of the hollow shaft 29 and can thus be actuated together from the side of the stamping press which has the fixed bearing 33. On the other side of the punch press, the drive assemblies 27 such as brake, clutch and flywheel with the crankshaft 9, 10, 29 are arranged.

In order to realize a balance of the moving masses, in each case, in addition to the tab 6, the front end of a mass balance lever 16 is hinged to each pin 6a. The center of this lever 16 is rotatably supported in a bolt fixed to the housing. The rear end of the lever 16 is pivotally connected to a counterweight 14 and drives this in operation in the opposite direction of the plunger 1. The mass forces in the stroke direction are compensated in this way. Furthermore, push rods 11 are present, which are arranged on the underside of the respective connecting rod 8 and via levers 13 drive the counterweights 14 in the opposite direction of the connecting rod 8, to compensate for the horizontal dynamic forces.

Fig. 3 shows a plan view of the punch press with removed press ram 1. The four tension columns 2 are shown in section. As can be seen, for each Zugsäule 2 an adjusting 35 with a servo motor 34 for the adjustment and possibly control of the ram height available. This servo geared motor unit 34, 35 drives for adjustment via a worm 36 to the worm wheel 18, which is an integral part of the threaded spindle 19. As a result, not only can set the ram height, but also compensate for any skewing of the plunger 1 due to an eccentric load. Further details of this ram height adjustment are in the left half of the Fig. 4 shown, which a horizontal section through one of the two machine housing 15, 15 b of the punch press from the FIGS. 1 to 3 shows.

If only eccentric loads in the longitudinal direction of the machine are expected, a variant with only one gear motor 34, 35 per machine housing 15, 15b is provided, as in the right half of Fig. 4 is shown. As can be seen, only two motor-gear units 34, 35 are used in this case for the four tension columns 2, wherein each of the arranged in a common machine housing 15, 15b screws 36 are connected to a hollow shaft 24.

Claims (20)

Punching press with a clamping plate (23) and with a top of the platen (23) opposite and against the platen (23) working press ram (1), which serve via tension columns (2), in particular as a guide for the press ram (1) , is drivable with a drive mechanism disposed below the punch plane, the drive mechanism having at least one crankshaft (9, 10, 29) with one or more associated connecting rods (8) for converting a rotary drive motion into an intermittent up and down motion for the drive of tension columns (2) of the press ram (1), characterized in that the crank shaft remote end of each connecting rod (8) at a first end of at least one lever (7) is hinged, which at its second end directly or indirectly to the structure (15, 15a, 15b) of the punch press is articulated, such that the lever (7) by rotating the crankshaft (9, 10, 29) through the Pl euel (8) can be pivoted back and forth around its second end, wherein the lever (7) in an area between its first and its second end is pivotally connected to at least one tension column (2) of the punch press, such that the tension column (2) can be moved up and down by pivoting the lever (7) back and forth. Punching press according to claim 1, characterized in that the vertical position of the articulation point of the respective lever (7) on the structure (15, 15a, 15b) of the punch press is adjustable, in particular during operation of the press. Punching press according to claim 2, characterized in that the vertical position of the articulation point of the respective lever (7) on the structure (15, 15a, 15b) of the punch press by means of a threaded spindle (19) is adjustable, in particular by means of a threaded spindle (19) driving servomotor (34, 35). Punching press according to one of claims 2 to 3, characterized in that a plurality of levers (7) are present, at their first ends in each case the crank shaft remote end of a connecting rod (8) is hinged, each at its second end directly or indirectly to the structure ( 15, 15a, 15b) of the punch press are hinged, such that the respective lever (7) by rotating the crankshaft (9, 10, 29) by the connecting rod (8) can be pivoted back and forth about its second end, and which in each case in an area between its first and its second end articulated with in particular exactly one, the respective lever (7) associated with the tension column (2) of the punch press are connected, such that the tension column (2) by pivoting back and forth of the lever ( 7) can be moved up and down, and wherein the vertical positions of the articulation points of the second ends of the levers (7) are adjustable in groups or independently. Punching press according to one of the preceding claims, characterized in that the respective lever (7) at its second end via a tab (7a) on the structure (15, 15a, 15b) of the punch press is articulated. Punching press according to one of the preceding claims, characterized in that the respective lever (7) in a region between its first and its second end via a tab (6) with the tension column (2) is connected. Punching press according to one of the preceding claims, characterized in that in each case a guide (21, 22) is present, by means of which the crankshaft remote end of the respective connecting rod (8) is guided vertically, such that its articulation point on the respective lever (7) exclusively in vertical direction is movable. Punching press according to claim 7, characterized in that the crankshaft remote end of the respective connecting rod (8) in a common pivot point at the first ends of two opposite, seen in the crankshaft longitudinal direction mirror image lever (7) is hinged, which in particular each seen in the crankshaft longitudinal direction in a mirror image manner with exactly one, the respective lever (7) associated Zugsäule (2) are connected. Punching press according to one of the preceding claims, characterized in that the crankshaft (9, 10, 29) extends in the longitudinal direction of the punching press, and in particular that exactly one longitudinally extending crankshaft (9, 10, 29) for driving all tension columns (2) is available. Punching press according to one of the preceding claims, characterized in that the punch press has exactly four tension columns (2), which are each arranged in the region of the outer corners of the plunger (1). Punching press according to claim 9 and according to claim 10, characterized in that the crankshaft (9, 10, 29) is arranged centrally along the longitudinal axis of the punch press, such that with respect to the tension columns (2) results in a symmetrical arrangement. Punching press according to claim 8 and claim 11, characterized in that the crankshaft (9, 10, 29) has exactly two crankpins (9, 10) which are arranged in each case in the region of one end of the crankshaft (9, 10, 29) and flanked at least on the side facing away from the respective shaft end by a radial bearing (30) of the crankshaft (9, 10, 29) assigned to this crank pin (9, 10), in particular designed as roller bearings. Punching press according to claim 12, characterized in that the crank pin (9, 10) each on both sides of a crank pin (9, 10) associated, in particular designed as a rolling bearing radial bearing (30, 33) of the crankshaft (9, 10, 29) are flanked. Punching press according to one of claims 12 to 13, characterized in that the crankshaft (9, 10, 29) in the region between those radial bearings (30) which are respectively arranged on the side facing away from the shaft end of the respective crank pin (9, 10), is designed as a hollow shaft. Punching press according to claim 14, characterized in that the crankshaft (9, 10, 29) is designed as a built shaft, such that the part formed as a hollow shaft (29) as the crank pin (9, 10) separate component (29) is. Punching press according to one of the preceding claims, characterized in that the crankshaft (9, 10, 29) is designed such that the lifting height of its crank pin (9, 10) is adjustable and in particular that the crankshaft (9, 10, 29) crank pin (9, 10) which are each formed by an eccentric (10) and an eccentric bushing (9) arranged rotatably on it, such that different lifting heights of the crankshaft (9) are produced by turning the eccentric bush (9) on the eccentric (10) , 10, 29) are adjustable. Punching press according to claim 16, characterized in that the eccentric (10) and eccentric bushes (9) of the respective crank pin (9, 10) in certain positions to each other with locking means (32), in particular with a locking pin (32), can be locked, for fixing a certain lifting height of the crankshaft (9, 10, 29). Punching press according to claim 14 and according to claim 17, characterized in that the locking means (32) via a central release mechanism (31) are releasable, which through the interior of the hollow shaft formed as part (29) of the crankshaft (9, 10, 29) extends. Punching press according to one of the preceding claims, wherein the crankshaft (9, 10, 29) is mounted in radial bearings (30, 33), characterized in that exactly one of the radial bearings (30, 33) of the crankshaft (9, 10, 29) as Fixed bearing (33) is formed, for receiving the forces acting on the crankshaft (9, 10, 29) axial forces. Punching press according to one of the preceding claims, wherein the crankshaft (9, 10, 29) is mounted in radial bearings (30, 33) each associated with one of the crankpins (9, 10), characterized in that the one or more crankpins ( 9, 10) assigned or assigned radial bearing (30, 33) in a separate housing part (15, 15b) is mounted or are each connected to a central, the platen (23) carrying or forming the housing part (15a), in particular screwed is.

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