EP2210680B1 - Bending press with a drive beam and elastically coupled bending beam - Google Patents

Description

The invention relates to a bending press as described in the preamble of claim 1 and a method as described in the preamble of claim 14.

From the document DE 41 38 286 A1 a press with a vertically movable upper cheek relative to a fixed lower cheek is known. The upper beam is divided approximately in two perpendicular to a direction of force action, the two cheek parts meet in the center of the cheek and are separated from one another on both sides of the joint by a gap with a gap width that increases continuously up to the cheek ends. This division of the upper beam makes it possible to achieve that the upper beam and the lower beam bend in the same direction under load at the work site and the deflection lines run at least approximately parallel. The two cheek parts of the upper cheek are preferably connected to one another by coupling members at their outer end regions, these coupling members being connected to the cheek parts via hinge axes and having spring elements, whereby a stable, neutral position is ensured in the unloaded state of the cheek part receiving the bending tool.

From the document EP 1 410 854 A1 a bending press with a fixed lower press beam and an upper press beam that can be adjusted relative thereto is known. Each of the two press beams comprises two outer beams arranged in parallel at a distance from one another and one inner beam each arranged between them. The opposing inner bars form support surfaces for bending tools on opposite end faces. These inner bars, which can be equipped with the tools, are each movable with respect to the outer bar and are coupled via resilient coupling elements, whereby a basic positioning of the bars of the bar structure is achieved. Depending on the elastic properties of the coupling elements, a relative movement of the inner beam parts with respect to the respective outer beam parts is made possible as a function of a load applied by the pressing forces. Through this design and coordination of the dimensions of the press beams and the coupling elements, the deflection of the beams that occurs under load can be coordinated with one another and thus the immersion depth of the interacting bending tools required for an exact bending angle is kept constant over the entirety of the bending length.

The object of the invention is to create a press with a two-part press beam with which the force required for a bending process can be brought into alignment with a line of action of a reaction force acting on the press beam, depending on the positioning of the tools in the longitudinal direction of the press beam.

This object of the invention is achieved by the features recited in the characterizing part of claim 1. The surprising advantage here is that during the forming process, deviations in the penetration depth of the bending tools in relation to the bending length, caused by bending of the press and table beams depending on the position of the tools, are compensated for by correcting the position of the part of the press beam that acts as a bending beam and so that a high angular accuracy is achieved on the workpiece.

However, an embodiment according to claim 2 is also advantageous, because it results in a change in the position of the drive beam relative to the bending beam by selecting appropriate adjustment paths for the drive means.

Due to the advantageous design, according to which the drive bar and the bending bar have mutually facing contact surfaces extending over a length of the drive bar, a direct force transmission between the drive bar and the bending bar is achieved.

However, designs according to claims 3 to 5 are also advantageous because, depending on the relative position of the drive beam, the position of the force introduction into the bending beam is variable over its length to adapt to a planned position of the bending tools.

An embodiment according to claim 6 is possible, as a result of which the required pivotability for adapting the position of the force transmission between the drive beam and the bending beam to the intended position of the bending tools is reduced.

However, claims 7 to 9 also describe structurally simple and technically advantageous designs.

However, an embodiment according to claim 10 is also advantageous because it also saves components and a preload for play-free contact of the contact surfaces of the drive beam and the bending beam is achieved.

Finally, however, designs according to claims 11 to 13 are also advantageous, whereby variants for forming the coupling element are available.

The object of the invention is also achieved by a method according to the measures according to claim 14. The advantage is that an approximately symmetrical deflection under load of the table beam and the bending beam is achieved whereby angular errors on the work part are largely avoided and readjustments of the adjustment paths of the drive means are not necessary in many cases.

However, measures as described in claim 15 are also advantageous, because by shifting the line of action of the deformation force and thus a force introduction point on the bending beam, the deformation effect during a correction deformation stroke from a central position, based on the bending length, into an eccentric, a post-forming of the workpiece is adjusted in particular the area to be subjected to and thus the forming quality is increased.

The invention is explained in more detail with reference to the embodiments shown in the figures.

Fig. 1

eine erfindungsgemäße Biegepresse in Ansicht;

Fig. 2

die Presse in Ansicht gemäß in Richtung II in Fig.1;

Fig. 3

eine Detaildarstellung des zweigeteilten Pressenbalkens, geschnitten gemäß den Linien III-III in Fig.4;

Fig. 4

der zweigeteilten Pressenbalken, geschnitten gemäß den Linien IV-IV in Fig.3;

Fig. 5

die erfindungsgemäße Biegepresse in Ansicht.

Show it:

Fig. 1

a bending press according to the invention in view;

Fig. 2

the press in view according to direction II in Fig.1 ;

Fig. 3

a detailed representation of the two-part press beam, cut along the lines III-III in Fig. 4 ;

Fig. 4

the two-part press beam, cut along lines IV-IV in Fig. 3 ;

Fig. 5

the bending press according to the invention in view.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference symbols or the same component designations, whereby the disclosures contained in the entire description can be transferred accordingly to the same parts with the same reference symbols or the same component names. The position details chosen in the description, such as for example above, below, to the side, etc., refer to the figure immediately described and shown and are to be transferred accordingly to the new position in the event of a change in position. Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

All information on value ranges in the present description should be understood to include any and all sub-areas, e.g. the information 1 to 10 should be understood to include all sub-areas, starting from the lower limit 1 and the upper limit 10 , ie all subranges begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, for example 1 to 1.7, or 3.2 to 8.1 or 5.5 to 10.

In the Figs. 1 and 2 a bending press 1, in particular a press brake 2, for producing work parts 3, between bending tools 4 that are adjustable relative to one another, is shown.

A machine frame 5 of the bending press 1 consists, for example, of a base plate 6 on which side walls 7, 8 are arranged, projecting vertically, spaced from one another and aligned parallel to one another. These are preferably connected by a massive cross bracing 9, formed for example from a sheet metal part, at their end regions spaced from the base plate 6.

The side cheeks 7, 8 are approximately C-shaped to form a free space for the reshaping of the workpiece 3, a fixed table beam 12 standing on the base plate 6 being attached to the front end surfaces 10 of legs 11 of the side cheeks 7, 8 close to the floor. Linear guide arrangements 15 for a press beam 16 which can be adjusted relative to the table beam 12 are provided on legs 14 of the side cheeks 7, 8 that are remote from the base plate 6. In the exemplary embodiment shown, the press beam 16 can be adjusted via two drive means 17, 18 of the drive arrangement 19, which are spaced apart from one another, according to double arrow 20. Thus, the reshaping and forming of the workpiece 3 is carried out between the bending tools 4 arranged on opposite support surfaces 21, 22 of the press beam 16 and the table beam 12 during an adjustment stroke of the press beam 16.

In the exemplary embodiment shown, the drive arrangement 19 is a hydraulic drive with hydraulic cylinders 23 acted on from both sides as the drive means 17, 18, with piston rods 24 being connected to the press beam 16 via spherical cap bearings 25 with the press beam 16, whereby a pivoting movement of the press beam 15 in a restricted area , by different adjustment paths of the drive means 17, 18, in one to one Front surface of the press beam 16 parallel plane is made possible and thus an immersion depth of the bending tools 4 can be influenced.

In the exemplary embodiment shown, the hydraulic cylinders 23 are fastened to the cross bracing 9 with housings 26. However, a design is also possible in which the housings 26 are fastened directly to the side walls 7, 8.

How better now Fig. 2 As can be seen, the press beam 16 is designed in two parts and consists of a drive beam 27 which is drive-connected to the piston rods 24 via the spherical cap bearings 25. The drive bar 27 protrudes into a slot-shaped receptacle 29, which extends over an entire length 28 of the press bar 16, of a bending bar 30 equipped with the bending tool 4, which is adjustably mounted in the linear guide arrangements 15 for vertical adjustment, whereby an adjustment of the bending tools 4 receiving support surfaces 21, 22 of the table beam 12 and of the bending beam 30 in planes 31, 32 aligned parallel to one another.

The drive beam 27 and the bending beam 30 have in the slot-shaped receptacle 29 facing contact surfaces 33, 34, the contact surface 33 of the drive beam 27 extending in an arcuate manner in the direction of the length 28, whereas the contact surface 34 of the bending beam 30 in the receptacle 29 is straight and runs in a plane 35 parallel to the plane 31 of the support surface 21 of the bending beam 30.
Via an elastic coupling element 36 which is arranged approximately in the middle of the length 28 and connects the drive beam 27 to the bending beam 30 - which will be discussed in more detail later - a play-free contact between the contact surfaces 33, 34 of the drive beam 27 and the bending beam 30 is possible in FIG the slot-shaped receptacle 29 guaranteed.

This is achieved in that the coupling element 36 according to the embodiment shown is formed by a spring assembly 37 in openings 38, 39 of the drive beam 27 and the bending beam 30, the spring force caused by the spring assembly 37 being greater than the dead weight of the bending beam 30 plus the occurring Acceleration forces that occur during an adjustment movement of the press beam 16 into an upper end position.

In the Figures 3 and 4 the elastic coupling of the drive beam 27 to the bending beam 30 by means of the coupling element 36, formed from the spring assembly 37, with a spiral compression spring 40 according to this exemplary embodiment, is shown in detail.

The drive beam 27 protrudes into the slot-shaped receptacle 29 of the bending beam 30, the contact surface 34 extending in the plane 35 and the curved contact surface 33 of the drive beam 27 facing it touching one another in a linear manner.

In the receptacle 29 of the bending beam 30 laterally delimiting legs 41, 42, the opening 38 crossing this is arranged in a rectangular shape. In the drive beam 27 and crossing it, the rectangular opening 39 is also arranged.

In relation to the contact surface 34 of the bending beam 30, a vertically measured distance 43 of the opening 38 is smaller than a distance 44 of the opening 39 in the drive beam 27, in relation to an apex 45 of the contact surface 33.

The openings 38, 39 and extending over a thickness 46 of the bending beam 30, an upper and a lower pressure plate 47, 48 are arranged, which bring about the preload in the openings 38, 39 via the spiral compression spring 40 arranged between them and thus the play-free contact of the contact surfaces 33, 34 between the drive beam 27 and the bending beam 30 in the receptacle 29 is achieved.

Lateral play of the pressure plates 47, 48 in the openings 38, 39 allows the drive bar 27 to be inclined relative to the bending bar 30 and thus "wandering" of the linear contact between the contact surfaces 33, 34 in the direction of the length 28 of the bending bar 30 and thus a change in a force line 49 as a function of an intended position of the bending tools 4 on the bending beam 30 and table beam 12 - as described below in the description of FIG Fig. 5 can be found.

In the Fig. 5 The bending press 1 is shown with the two-part press beam 16, consisting of the drive beam 27 frictionally coupled to the drive arrangement 19 and the bending beam 30 adjustable in the guide arrangements 15 - according to arrow 50 - and the method according to the invention is explained in the following description.

The assembly of the bending press 1 with the bending tools 4 in the bending beam 30 and the table beam 12 shows an eccentric arrangement of the bending tools 4 as is often chosen when, for example, several sets of tools are used for different bending processes over the length 28 of the bending beam 30.

Such assembly means different force application at the force introduction points, for example the spherical ball bearings 25 and an asymmetrical design of the deflection that occurs during the bending process on the bending beam 30 and table beam 12, with conventional bending presses with one-piece press beams then leading to bending inaccuracies because the depth of immersion of the Bending tools 4 turn out differently in the case of an eccentric arrangement and thus lead to inaccuracies in an adjustment path which is predetermined for a certain bending angle and which is measured and controlled.

In the embodiment shown with the two-part press beam 16, consisting of the drive beam 27 with the arched contact surface 33 and the power transmission to the contact surface 34 of the bending beam 30 extending in the plane 35, an inclined position of the drive beam 27, which connects the elastic coupling element 36 enables the line of force 49 to transfer the pressure force between the drive beam 27 and the bending beam 30 in the direction of the length 28 and thus for the forming process of the workpiece 3, due to the eccentricity of the assembly with the bending tools 4 occurring reaction force, according to - arrow 50 - in brought aligned agreement.

The pivoting of the drive beam 27 takes place through different adjustments of the drive means, whereby, as shown, the pin bearings 25 assume a correspondingly different position and a pivoted position of the drive beam 27 is achieved.

The maximum inclination of the drive beam 27 from its horizontal neutral position is once a segment height 51 of the curved contact surface 33, the segment height 51 being selected as a function of the respective length 28 of the drive beam 27. For the intended function of positioning the force transmission point of the drive beam 27 according to the position of the tool set, only a small one is required Segment height 51, to an extent between about 0.2% to about 2.0% of the length 28 of the drive beam 27 is sufficient.

Next is that Fig. 5 an embodiment of the coupling element 36 between the drive beam 27 and the bending beam 30 is shown, which is formed from at least one pressure-elastic plastic pad 52, which ensures the play-free contact of the contact surfaces 33, 34, regardless of the position of the drive beam 27, as well as the relative movement between the drive beam 27 and the bending beam 30 during a pivoting movement of the drive beam 27.

The bending press 1 according to the invention with the two-part press beam 16 enables, as already partially described previously, the force introduction point on the bending beam 30 by pivoting the drive beam 27 by means of appropriately preselected adjustment paths of the drive means 17, 18 in an aligned position with the force line 49 of the for a forming process on the Work part 3 to be applied force to bring.

This is preferably done automatically when data stored in a work program is called up, for example according to parameters stored in a data memory, e.g. position of the tool sets or an assembly diagram of the bending press 1, with one or more bending stations from cooperating bending tools, the bending length, the work part data, the Geometry of the drive beam 27 etc.

After positioning the drive beam 27, the forming process takes place by adjusting the drive beam 27 in the pivoted position by the same adjustment path of the drive means and thus the adjustment of the bending beam 30 takes place by the adjustment path required for a predetermined deformation, e.g. bending angle, to achieve a for the bending angle required immersion depth of the bending tools.

Due to the fact that the force application point on the bending beam matches the position of the force line, there is almost no force-related deflection on the bending beam and only the deflection of the table beam that can be detected in its magnitude, e.g. from a data matrix stored in the data memory, needs to be taken into account for high-quality forming.

In order to achieve this, it is also possible, for example, to carry out a relief return stroke with the drive means after the forming stroke has taken place and to measure the angle achieved on the workpiece and thus to determine any inaccuracies and to correct it by performing a new forming stroke, specifying a correction factor for the immersion depth. It is also possible, particularly advantageous for large bending lengths, to place the force application point during the forming stroke, which is the same as the point of contact of the contact surfaces 33, 34, and thus the line of force 49 in the direction of the longitudinal extension of the bending tools 4, by means of an automated readjustment of the pivot position of the drive beam 27 to change.

The exemplary embodiments show possible design variants of the bending press 1, whereby it should be noted at this point that the invention is not limited to the specifically shown design variants of the same, but rather various combinations of the individual design variants with one another are possible and this possible variation is based on the teaching on technical action The present invention is within the ability of those skilled in this technical field. All conceivable design variants that are possible through combinations of individual details of the embodiment variants shown and described are therefore also included in the scope of protection of the appended claims.

For the sake of clarity, it should finally be pointed out that, for a better understanding of the structure of the bending press, it or its components have been shown partially not to scale and / or enlarged and / or reduced.

List of reference symbols

1 Bending press 41 leg 2 Press brake 42 leg 3 Work part 43 distance 4th Bending tool 44 distance 5 Machine frame 45 Vertex 6th Base plate 46 thickness 7th Sidewall 47 printing plate 8th Sidewall 48 printing plate 9 Cross brace 49 Force line 10 Front mouth 50 arrow 11 leg 51 Segment height 12th Table beam 52 Pressure pad 13 Front mouth 14th leg 15th Guide arrangement 16 Press beam 17th Drive means 18th Drive means 19th Drive arrangement 20th Double arrow 21st Support surface 22nd Support surface 23 Hydraulic cylinder 24 Piston rod 25th Spherical spherical bearings 26th Pressure housing 27 Drive beam 28 length 29 admission 30th Bending beam 31 level 32 level 33 Contact area 34 Contact area 35 level 36 Coupling element 37 Spring package 38 breakthrough 39 breakthrough 40 Spiral compression spring

Claims (15)

1. A bending press (1), in particular a press brake (2), with a machine frame (5), with side walls (7, 8) and a fixed table beam (12) distancing the side walls, and with a press beam (16) adjustable relative to the table beam (12) in linear guide arrangements (15) of the machine frame (5), with a driving arrangement (19) consisting of at least two driving means (17, 18) distanced from one another,

   - wherein the press beam (16) is formed by a driving beam (27) drive-connected to the driving means (17, 18)

   - and a bending beam (30) that is movement-connected thereto by means of at least one elastic coupling element (36), characterized in that

   - the bending beam (30) has a slit-shaped receptacle (29) extending over an entire length (28) of the press beam (16)

   - and the driving beam (27) protrudes into said receptacle (29),

   - wherein the driving beam (27) and the bending beam (30) have contact surfaces (33, 34) facing each other in the slit-shaped receptacle (29),

   - wherein the contact surface (34) of the bending beam (30) extends in a straight line and in a plane (35) parallel to a plane (31) of a support surface (21) of the bending beam (30)

   - and wherein the contact surface (33) of the driving beam (27) extends curved in an arc-shaped manner in the direction of the length (28) of the driving beam (27).
2. The bending press (1) according to claim 1, characterized in that the driving beam (27) is connected to the bending beam (30) in a pivotable manner by means of the coupling element (36).
3. The bending press (1) according to one of the preceding claims, characterized in that the contact surface (33) of the driving beam (27) is formed so as to be curved in a convex manner.
4. The bending press (1) according to one of the preceding claims, characterized in that the contact surface (33) of the driving beam (27) extends curved in the shape of a circular arc.
5. The bending press (1) according to one of the preceding claims, characterized in that the driving arrangement (19) with the driving means (17, 18) is configured for an adjusting stroke that is optionally equal or different depending on the driving means (17, 18).
6. The bending press (1) according to one of the preceding claims, characterized in that a segment height (51) of the contact surface (33) measured in the middle of the length (28) of the driving beam (27) amounts to about 0.2% to 2.0% of the length (28) of the driving beam (27).
7. The bending press (1) according to one of the preceding claims, characterized in that the driving beam (27) and the bending beam (30) are formed so as to overlap with wall parts in the adjusting direction.
8. The bending press (1) according to one of the preceding claims, characterized in that a base surface of the receptacle (29) forms the contact surface (34) of the bending beam (30).
9. The bending press (1) according to one of the preceding claims, characterized in that the contact surface (34) of the bending beam (30) extends in a plane parallel to the tool support surface (22).
10. The bending press (1) according to one of the preceding claims, characterized in that the coupling element (36) is arranged approximately in the middle of the length (28) of the driving beam (27) in openings (38, 39) traversing the driving beam (27) and the bending beam (30).
11. The bending press (1) according to one of the preceding claims, characterized in that the coupling element (36) is formed by a spring assembly (37) having at least one recoil spring (40).
12. The bending press (1) according to one preceding claims, characterized in that the coupling element (36) is formed by at least one hydro spring element.
13. The bending press (1) according to one of the preceding claims, characterized in that the coupling element (36) is formed by at least one plastic pressure pad traversing the openings (38, 39).
14. A method for operating a bending press (1), in particular a press brake (2), with a machine frame (5), with side walls (7, 8) and a fixed table beam (12) distancing the side walls (7, 8), and with a press beam (16) adjustable relative to the table beam (12) in linear guide arrangements (15) of the machine frame (5), with a driving arrangement (19) consisting of at least two driving means (17, 18) distanced from one another, wherein the press beam (16) is formed by a driving beam (27) drive-connected to the driving means (17, 18) and a bending beam (30) that is movement-connected thereto by means of at least one elastic coupling element (36), characterized in that the driving beam (27) and the bending beam (30) have contact surfaces (33, 34) facing each other and extending over a length (28) of the driving beam (27), and that upon starting a deformation process, the predefined position of the corresponding bending tool set starting from a 0-coordinate of the table beam (12), which coordinate is defined by a force action line of one of multiple driving means (17, 18) for applying a pressing force to the bending beam (30), is obtained from a work program, and subsequently, an angular position for the driving beam (27) is determined according to the geometry of the driving beam (27), in a computer of a control and adjustment device of the bending press (1), and said angular position is adjusted by controlling the driving means (17, 18) for an adjustment track of at least one of the driving means (17, 18), at which a position of the contact surface (33), extending curved in an arc-shaped manner, of the driving beam (27) is reached, in which the force action line of the deformation force to be applied is in an aligned orientation with a force action line (49) of a reaction force acting on the bending beam (30) due to the deformation process, and subsequently, the control of the driving means (17, 18) that are drive-connected to the driving beam (27) for adjusting the bending beam (30) into an engagement position of the bending tools (4) intended for the predefined deformation process on the workpiece (3) is carried out.
15. The method according to claim 14, characterized in that after reaching the intended engagement position, the driving means (17, 18) are controlled for a load relief stroke, and subsequently, the deformation on the workpiece (3), in particular a deformation angle, is measured, and when an angle deviation is detected, a new engagement position is calculated and controlled by adjusting the press beam (16), wherein, during the correction deformation stroke, a shifting of the force action line in the direction of the bending length is carried out by pivoting the driving beam (27) for compensating possible different angle deviations with respect to a bending length.

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