EP0724953B1 - Punch press with extended space for mounting dies - Google Patents

Abstract

The relevant characteristics of the invention include the fact that the drive from the eccentric (1) is divided symmetrically and delivered - via respective lever and link configurations - to the two punches (32, 32a). This allows the press tool space (53) to be lengthened without excessive increase in the press loading and in the mass of moving elements.

Description

The present invention relates to a punch press with a press housing, at least one ram, a punching space, a device for generating a lifting movement, in which punching space a strip running plane of a respective strip to be processed to be fed in a strip feed direction through the punching space and to be processed is fixed.

In modern stamping technology, the development is moving towards the complete processing of a raw material, i.e. the complete chipless manufacture of a product. This means that a punch press is formed into a complete manufacturing center. In addition to the usual cutting and forming (bending) operations, assembly and joining work is also increasingly being carried out in punching presses, welding, riveting and threading are also being formed. After each processing step of a strip to be processed, the strip is advanced by a predetermined distance in the punch press. Measuring devices for quality assurance are also increasingly being used during ongoing work processes. This means that the length of the tool installation space, i.e. the punching space, the longer the more individual work steps are carried out in the punch press. As a result, longer and longer tool installation spaces are required.

In order to obtain a longer tool installation space, all that would really need to be done was to enlarge a conventional press construction to scale. However, this increases the permissible nominal load, based on the square, and the masses with the third power.

In practice, however, higher nominal loads are rarely required for longer tool installation spaces. The extreme growth of the masses, especially the moving masses, is even undesirable.

So scaling up a punch press to achieve a longer tool installation space results in an excessively high machine price, low machine speeds, a large amount of energy and dynamic mass forces that are difficult to control, particularly in the case of the manufacture and processing of fine and high-precision parts.

The invention seeks to remedy this. The object of the invention is to provide a punching machine which has a long tool installation space, but permits high machine speeds, does not require increased energy expenditure and does not cause excessively high dynamic inertia forces.

The punching machine according to the invention, as characterized in claim 1, has a device for generating a lifting movement which is articulated at one end of a respective plate group at at least two points which are at a distance from one another in the strip running direction and carry out lifting movements during operation of the punch press Lugs are articulated at their opposite ends at a respective end defining a articulation area at a first end of double levers of respective pairs of double levers, the individual double levers of each pair of double levers pointing in opposite directions with respect to the articulation area and being mounted at rocker bearing positions that are relative to one another in relation to the articulation area are symmetrically opposite, which double levers are hinged at their second end to a pressure column.

The advantages achieved by the invention can be seen in particular in the fact that an extremely long tool installation space is made possible, but high machine speeds, a limited power requirement and low dynamic mass forces prevail.

Further goals and advantages result from the dependent claims.

In the following, the subject matter of the invention is explained in more detail, for example, with the aid of drawings showing the ways of implementation.

• Figur 1 einen Schnitt durch eine Stanzpresse,
• Figur 2 einen Schnitt entlang der Linie II-II der Figur 1,
• Figur 3 in vergrössertem Massstab einen Ausschnitt aus der Figur 1,
• Figur 4 einen Schnitt entlang der Linie IV-IV der Figur 3,
• Figur 5 einen Schnitt entlang der Linie V-V der Figur 3,
• Figur 6 einen Schnitt entlang der Linie VI-VI der Figur 3, und
• Figur 7 einen Schnitt entlang der Linie VII-VII der Figur 1.

It shows:

• FIG. 1 shows a section through a punch press,
• FIG. 2 shows a section along the line II-II in FIG. 1,
• FIG. 3 shows an enlarged section of FIG. 1,
• FIG. 4 shows a section along the line IV-IV in FIG. 3,
• FIG. 5 shows a section along the line VV of FIG. 3,
• 6 shows a section along the line VI-VI of Figure 3, and
• 7 shows a section along the line VII-VII of FIG. 1.

In the following description, an eccentric shaft with associated components is described as an exemplary embodiment of a device for generating a lifting movement. However, other designs of the device for generating a lifting movement are also possible, for example devices containing a crankshaft, hydraulic drives, drives containing cams, etc.

The punch press of the embodiment shown has an eccentric shaft 1 which is supported at its ends in main bearings 2a, 2b in the press housing 2. The eccentric shaft 1 is driven, for example, via a clutch and brake device 3. Such clutch and brake devices for punch presses are generally known, so that a detailed description is unnecessary. The eccentric shaft 1 has an eccentric section 4. In the embodiment shown, this eccentric section 4 is a one-piece section of the eccentric shaft 1. However, versions are obviously also possible in which the stroke adjustment of the tappet Punching press are present in the eccentric section 4 rotatable sleeves. Such arrangements for stroke adjustment are known and express reference is made to CH-A-574 323 and US-A-4 160 409. On the eccentric section 4, two connecting rods 5, 5a arranged next to one another are supported by roller bearings. A connecting rod bolt 6 is arranged at the lower ends of the connecting rods 5, 5a. The connecting rod pin 6 has end sections 6a, 6b, on which end sections 6a, 6b a sliding block 11a, 11b is arranged, which sliding blocks 11a, 11b are guided in sliding block guides 12a, 12b.

Due to the components described so far, the rotary movement of the eccentric shaft 1 is converted into a linear stroke movement of the connecting rod pin 6 during operation of the punch press.

One-armed levers 7, 7a, 8 and 8a are mounted on the connecting rod bolt 6. At their opposite ends, the one-armed levers 7, 7a, 8 and 8a are articulated via bolts 13, 13a, 13b and 13c and tabs 14, 14a, 14b and 14c to respective spindle nuts 15, 15a, which are each arranged on a threaded spindle 16, 16a are.

The sliding blocks 11a, 11b and sliding inlets 12a, 12b thus form a device by means of which one end of the one-armed levers 7, 7a, 8, 8a are guided in the direction of the lifting movement.

From the drawings it can be seen that there are a total of four bolts 13-13c, four tabs 14-14c, two spindle nuts 15, 15a and two threaded spindles 16, 16a.

The one-armed levers 7, 7a, 8 and 8a are thus supported on the press housing 2 at their ends opposite the connecting rod bolts 6. These ends are, as will be described in more detail below, supported in a height-adjustable manner, whereby the height of the plunger 32, 32a can be changed.

At a point between the described ends of the one-armed lever 7, 7a, 8 and 8a a bolt 18 or 18a is pressed in at a bearing 17 or 17a. The bearing points 17, 17a are points which perform stroke movements when the punch press is in operation, for the sake of completeness it should be noted that these are non-linear movements.

Tabs 19, 19a, 19b and 19c are mounted on the bolts 18 and 18a at one of their ends, each forming a tab group. These tabs 19, 19a, 19b and 19c are supported at their lower ends on axially aligned bolts 20, 21, 20b and 20a, 21a, 20c.

These bolts 20, 21, 20b and 20a, 21a, 20c are used in pairs of double levers.

Here, see Figure 1 and in particular Figure 5, the pin 21 is inserted in the double lever 23. The bolts 20, 20b are inserted in the double lever 22.

In the same way, the bolt 21a is inserted in the double lever 23a and the bolt 20a, 20c in the double lever 22a.

The double lever 23 is mounted on a pin 24 which defines a rocking bearing point and which is in turn mounted in the press housing 2.

The double lever 22 is mounted on a pin 25 which defines a further rocking bearing point and which is in turn mounted in the press housing 2.

Correspondingly, the double lever 23a is mounted on the pin 24a and the double lever 22a on the pin 25a.

At the opposite end, the double lever 23 is articulated on a pressure column 28 by means of a pin 26, and at its opposite end the double lever 22 is articulated on a pressure column 29 by means of a pin 27.

In the same way, in the pair of double levers 22a and 23a arranged on the right in FIG. 1, the double lever 22a is articulated on the pressure column 29a and the double lever 23a on the pressure column 28a.

The pressure columns 28 and 29 are connected to the plunger 32 by means of bolts 30 and 31, and the pressure columns 28a and 29a are connected to the plunger 32a by means of bolts 30a and 31a.

Alternatively, all four pressure columns 28, 28a, 29, 29a could also be connected to only a single tappet, or each of the pressure columns could be connected to its own tappet.

The arrangement of the tappet guides is now described below, reference being made in particular to FIGS. 3 and 4.

The plunger 32 is firmly connected to two downwardly projecting guide columns 35, 35b. The guide columns 35, 35b are guided in the tape running plane 36 in guides 33, 33b and the guide columns 35a, 35c in guides 33a, 33c. This guide arrangement is described in detail in CH-A-568 848 and US-A-3 998 498 and reference is made to these documents for reasons of disclosure.

The plungers 32, 32a additionally contain a further, that is to say third, guide 34 or 34a, which are arranged above the belt running plane 36. Further guide columns 37, 37a firmly connected to the press housing 2 protrude into these third guides 34 and 34a, respectively. The guides 34, 34a have sliding surfaces 38 (Fig. 4), (see the documents cited above), which in the longitudinal direction of the punch press, i.e. run in the tape feed direction. The guides 34, 34a thus prevent the plungers 32, 32a from deflecting in the transverse direction of the punch press, but, due to the sliding surfaces 38, allow the plungers 32, 32a to expand thermally without the plunger guides 33, 33b; 33a, 33c; 34, 34a to brace.

In the figures, the platen of the punch press is identified by reference number 39 and its base plate by reference number 40.

Eccentric in relation to the longitudinal direction of the punch press or tape feed direction Punching load F (FIG. 3) between, for example, the plunger 32 and the mounting plate 39 or base plate 40, the pressure columns 28, 29 are deformed differently elastically. The plunger 32 assumes an inclined position, as indicated in FIG. 3 by the distance S, the (exaggeratedly drawn) inclined position of the plunger 32 being represented by the dashed line T. The elastic deformation and change in position of the pressure column 29 are shown by the dashed line U and correspondingly in the pressure column 28 by the dashed line V. Furthermore, the inclination of the guide column 35 is shown by the dashed line W.

Because the guides 33, 33b are arranged on the belt running plane 36, the tipping point K of the plunger 32 remains on the belt running plane 36. This means that the plunger 32 or the tool 51 (upper tool) connected to it does not on the belt running plane 36 deflects.

The guide 34 or its running surfaces 38 (FIG. 4) allow a corresponding shift. The seals 52, 52b between the press housing 2 and the pressure columns 28, 29 are movable seals which, even when the plunger 32 is inclined, prevent oil from escaping from the closed press housing 2 into the working space and contaminating the strip to be processed and the tools.

The behavior of the various components when the plunger 32 is eccentrically loaded has now been described. Exactly the same behavior of the corresponding components appears when the plunger 32a is eccentrically loaded.

FIG. 5 shows a section along the line V-V of FIG. 3, and in particular a section through the double levers 22, 23.

The pull tab group 19, 19a articulated on the one-arm lever 7, 8 contains inner pull tabs 19b which are connected to the inner bolt 21 which is inserted in the end of the double lever 23. During operation, these inner pull tabs 19b transmit the force symmetrically via the double lever 23 supported on the pin 24 at the luffing bearing point to the pin 26 and thus to the pressure column 28. The outer pull tabs 19 are connected to the outer pins 20, 20b, which in End of the double lift 22 are used. During operation, these outer pull tabs 19 transmit the force symmetrically via the double lever 22 supported on the pin 25 at the luffing bearing point to the pin 27 and thus to the pressure column 29.

The same corresponding design of the corresponding components is present in the one-armed lever 7a, 8a, double lever 22a, 23a, etc. arranged on the right in FIG.

FIG. 6 shows a section along the line VI-VI of FIG. 3 and in particular a section through the single-armed levers 7, 8, 7a and 8a, only the levers 7 and 8 arranged on the left in FIG. 1 being shown completely in FIG. 6 are. The following description again relates to the components arranged on the left in accordance with FIG. 1.

The load transmitted by the plunger 32 via the components described above during operation of the punch press is partly transmitted through the inner pull tabs 19b to the common bolt 18 and thus symmetrically to the bearing points 17 of the one-armed lever 7, 8. The other part of the load is also transmitted through the outer pull tabs 19 to the common bolt 18 and thus symmetrically to the bearing points of the one-armed lever 7, 8.

The one-armed levers 7, 8, on the one hand, transfer the load acting on the bolt 18 or bearing 17 via the bolt 6 and the connecting rods 5, 5a (FIGS. 1, 2) to the eccentric section 4 of the eccentric shaft 1, which is in the main bearings 2a , 2b is supported in the press housing 2.

On the other hand, the load at the opposite end of the one-armed lever 7, 8 is transmitted via the bolts 13, 13b, the tabs 14, 14b, the spindle nut 15 to the threaded spindle 16, which is however rotatably supported on the press housing 2 in a stationary manner.

With this latter arrangement of components, the height position of the plunger 32 can be adjusted.

For this purpose, the threaded spindle 16 has a worm wheel 43 which meshes with a worm 42 (FIGS. 5, 6). The spindle nut 15 has an extension 44 which projects into a guide groove 45 of the press housing 2, with which the spindle nut 15 is secured against rotation. The worm 42 is driven by a servo motor 41.

If the worm 42 is rotated by the servo motor 41, it causes the threaded spindle 16 to rotate and thus causes the spindle nut 15 to be displaced in the vertical direction. This displacement movement is carried out via the tabs 14, 14b on the bolt 13 and thus on the lever pairs 7, 8 or 7, 11 transmitted.

The opposite connecting rod pin 6 is fixed in its position with respect to a respective position of the eccentric shaft 1. Consequently, the connecting rod pin 6 forms the pivot center of the pairs of levers 7, 8 when they are moved through the tabs 14, 14b. Thus, a vertical movement of the tabs 14, 14b generated by the servo motor 41, the worm 42, the worm wheel 43 and the threaded spindle 16 causes a pivoting movement of the bolt 18 and thus an upward or downward movement of the tabs 19, 19b. This movement is transmitted via the double levers 22, 23 to the pressure columns 28, 29, with the result that the plunger 32a is finally displaced in its vertical position.

Because each threaded spindle 16, 16a is connected to its own servo drive, the height of the two plungers 32, 32a can be adjusted synchronously or separately from one another. When the punch press is running, each ram 32, 32a can be adjusted independently of the other ram 32a, 32 in steps of less than 10 μm in its height.

Each punch press needs training to balance the moving masses, and a wide variety of designs, including mass balancing weights, are known.

The mass balancing of the punch press will now be described. Because the moving masses are the same in mirror image with respect to the vertical center line of FIG. 1, only the configuration of the components arranged to the left of this center line or axis of symmetry is described with regard to the mass compensation.

The total mass of the guide columns 35, 35b, the plunger 32, the pressure columns 28, 29 and the section of the double levers 22, 23 which, from their articulation point on the pressure columns 28, 29 (bolts 26, 27) to the rocker bearing point, i.e. Bolt 24, 25 extends, is the same size as the total mass of the section of the double lever 22, 23, which from the rocker bearing point, i.e. Bolts 24, 25 extend to the link point on the tabs 19, 19b, the tabs 19, 19b, the one-armed levers 7, 8, the sliding blocks 11a, 11b, the connecting rods 5, 5a and the connecting rod bolts 6, 6a, 6b of the eccentric section 4 , the elongated upper ends 9, 9a of the connecting rods 5, 5a, the links 47, 47a articulated to the upper ends 9, 9a and the bolts 46, 46a. This means that the oscillating masses of the punch press, including the vertical component of the rotating unbalance, are balanced during operation, which means that there is no need for additional counterweights to compensate for the masses oscillating in the vertical direction, including the rotating unbalance in the vertical direction, which are the mass forces and the associated friction would increase unnecessarily.

To balance the horizontal component of the rotating unbalanced mass, see Figure 1, Figure 2 and Figure 7, the links 47, 47a, which are articulated via the bolts 46, 46a to elongated upper ends 9, 9a of the connecting rods 5, 5a, are connected at their opposite ends via bolts 48, 48a, each with a counterweight 49, 49a. These counterweights 49, 49a are mounted on bolts 50, 50a. The bolts 50, 50a are arranged at such a point in the press housing 2 and the counterweights 49, 49a are mounted on the bolts 50, 50a in such a way that their centers of mass M, Ma at the respective reversal point of the counterweights 49, which pivot in the opposite direction to the eccentric section 4. 49a are at least approximately at the height of the central axis 10 of the eccentric shaft 1, as indicated by the dash-dotted line 10 in FIGS. 1 and 7.

Claims (14)

1. Punch press, with a press frame (2), at least one punch (32;32a), a punching space (53), a device (1, 5, 6, 11a, 12a, 7, 7a, 8, 8a) for the producing of a stroke movement, in which punching space (53) a plane (36) of advance of a web to be fed through the punching space and to be processed is set, characterized in that the device (1, 5, 6, 11a, 12a, 7, 7a, 8, 8a) for the producing of a stroke movement is pivotally mounted at least at two points (18, 18a) located at a distance from each other in the direction of the advance of web and executing stroke movements during operation of the punch press to one end of a respective group of links (19, 19a; 19b, 19c), of which the links (19, 19a, 19b, 19c) are pivotally mounted at their opposite end at a respective point (20, 21, 20b; 20a, 21a, 20c) determining a pivotal area to a first end of double levers (22, 23; 22a, 23a) of respective double lever pairs, whereby the individual double levers (22, 23; 22a, 23a) of each double lever pair project relative to the pivotal area in opposite directions and are supported at rocking bearing points (24, 25; 24a, 25a) which are located relative to the pivotal area (20, 21, 20b; 20a, 21a, 20c) symmetrically opposite of each other, which double levers (22, 23; 22a, 23a) are pivotally mounted and their second ends to a pressing column (28, 29; 28a, 29a).
2. Punch press according to claim 1, characterized in that the double levers (22, 23; 22a, 23a) of each double lever pair are arranged in succession relative to the direction of feed of the web.
3. Punch press according to claim 1 or 2, characterized in that two double lever pairs are present and arranged in succession relative to the direction of feed of the web.
4. Punch press according to one of the preceding claims, characterized in that the device (1, 5, 6, 11a, 12a, 7, 7a, 8, 8a) for the production of a stroke movement is pivotally mounted at two points (18, 18a) which perform stroke movements during operation of the punch press to one end of groups of links (19, 19b; 19a, 19c), which points are located at the same distance from a plane of symmetry of the machine frame (2) extending perpendicularly to the direction of feed of the web.
5. Punch press according to one of the preceding claims, characterized in that two double lever pairs are present, of which the double levers (22, 23; 22a, 23a) are pivotally mounted to a respective pressing column (28, 29; 28a, 29a), so that the punch press comprises four pressing columns (28, 29; 28a, 29a).
6. Punch press according to one of the preceding claims, characterized in that the pressing columns (28, 29;, 28a, 29a) of each double lever pair are pivotally mounted to one ram (32; 32a).
7. Punch press according to one of the preceding claims, characterized in that the rams (32; 32a) are arranged at a distance from each other in the direction of the plane (36) of advance of the web.
8. Punch press according to one of the preceding claims, characterized in that each ram (32; 32a) includes at one end area two guiding columns (35, 35b; 35a, 35c) arranged at a distance from each other, which are guided in guiding units (33, 33b; 33a, 33c) mounted to the press frame and located in the plane (36) of advance of the web.
9. Punch press according to claim 8, characterized in that at the area of each ram (32; 32a) a further guide column (37; 37a) located at a distance of its two guiding columns (35, 35b; 35a, 35c) is rigidly mounted to the press housing (2) which projects into a further guiding unit (34; 34a) which is arranged above the plane (36) of advance of the web, so that each ram (32; 32a) is guided at three locations.
10. Punch press according to one of the preceding claims, characterized in that the device (1, 5, 6, 11a, 12a, 7, 7a, 8, 8a) for the production of a stroke movement includes two single arm levers (7, 8; 7a, 8a) which are mounted at their first end to a device by means of which this first end is guided in the direction of the stroke movement, and are supported at their second, opposite end at the press housing (2), whereby the pivotal points (18; 18a) of the respective link groups (19, 19b; 19a, 19c) which perform stroke movements are located between the ends of the single arm levers (7, 8; 7a, 8a), which single arm levers (7, 8; 7a, 8a) are supported at their second ends via threaded spindles (16; 16a) in a height-adjustable manner at the press housing, so that the height position of the second end of each single arm lever (7, 8; 7a, 8a) and accordingly the height position of the ram (32; 32a) connected thereto is adjustable independently from or synchronously with any further ram (32; 32a).
11. Punch press according to one of the preceding claims, characterized in that the total mass of the guide columns (35, 35b; 35a, 35c), the rams (32, 32a), the pressing columns (28, 29; 28a, 29a) and the respective section of the double levers (22, 23; 22a, 23a) which extends from their pivotal points at the pressing columns (28, 29; 28a, 29a) up to the rocking bearing point (24, 25; 24a, 25a) equals the total mass of the respective section of the double levers (22, 23'; 22a, 23a) which extends from the rocking bearing point (24, 25; 24a, 25a) up to the pivotal point at the links (19, 19b; 19a, 19c), the links (19, 19b; 19a, 19c), the single arm levers (7, 8; 7a, 8a), the sliders (11a, 11b), the connecting rods (5, 5a) and the connecting rod pin (6, 6a, 6b), the eccentric portion (4), the extended upper ends (9, 9a) of the connecting rods (5, 5a), the bars (47, 47a) pivotally mounted to the upper ends (9, 9a) and the pins (46, 46a).
12. Punch press according to one of the preceding claims, characterized in that the device (1, 5, 6, 11a, 12a, 7, 7a, 8, 8a) for the production of a stroke movement includes an eccentric shaft (1) and a connecting rod unit (5, 5a) supported on the eccentric shaft (1) which includes a first end with a slider (11a, 11b) guided in a slider guide (12a, 12b), onto which single arm levers (7, 8; 7a, 8a) are pivotally mounted which are supported height-adjustably at the opposite end at the press frame (2), to which the respective link groups (19, 19a; 19b, 19c) are pivotally mounted, which connecting rod unit (5, 5a) is pivotally mounted at a second end (9, 9a) located relative to the eccentric shaft (1) diametrically opposite of the first end to a lateral bar (47, 47a) which at both ends is pivotally mounted to a respective eccentrically supported balancing weight part (49; 49a), which balancing weight parts (49; 49a) are intended to balance the horizontal components of the rotating unbalanced mass of the punch press.
13. Punch press according to one of the preceding claims, characterized in that the device (5, 6, 11a, 12a, 7, 7a, 8, 8a) for converting the rotary motion of the eccentric shaft (1) into a stroke movement comprises at least one connecting rod (5, 5a) supported on an eccentrically structured section (4) of the eccentric shaft (1), which includes an end which is guided in a device (11, 11a; 12, 12a) for a rectilinear guiding, which device (11, 11a; 12, 12a) for a rectilinear guiding includes a guiding slider (11, 11a) with a pin (6, 6a, 6b), onto which pin (6, 6a, 6b) the end of the connecting rod (5, 5a) is pivotally mounted, which guiding slider (11, 11a) is mounted to force transmitting members (7, 8, 19, 19b; 7a, 8a, 19a, 19c) which in turn are pivotally mounted to one end of double levers (22, 23; 22a, 23a) of respective double lever pairs, which double levers (22, 23; 22a, 23a) are supported at rocking support points (24, 25; 24a, 25a) and include a second end to which a pressing column (28, 29; 28a, 29a) is pivotally mounted which is connected to a ram (32; 32a), so that the ram (32; 32a) is connected via two pressing columns (28, 29; 28a, 29a) to a respective double lever pair.
14. Punch press, according to one of the preceding claims, in which at least two rams (32; 32a) are present, characterized in that each ram (32; 32a) is guided by three guiding columns (35, 35b, 37; 35a, 35c, 37a), of which two (35, 35b; 35a, 35c) are rigidly mounted to the ram (32; 32a) and one is rigidly mounted to the housing (2) of the punch press.

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