Bending Machine

Abstract

The invention relates to a bending machine, wherein the bending machine (100; 200) has a bending beam (105; 205, 205') which can be moved in at least one working direction (z) of the bending machine (100; 200) to shape a workpiece by bending along a bending line extending in a width direction (y) of the bending machine (100; 200), wherein the bending machine (100; 200) comprises a holding device (113; The invention relates to a bending machine (100; 200) and a bending machine (100; 200) for fixing at least one bending tool (109; 209) on the bending machine (100; 200), wherein a release device (116; 216) is provided on the bending machine (100; 200) to move the holding device (113; 213) from a closed position in which the at least one bending tool (109; 209) is fixed to an open position in which the at least one bending tool (109; 209) is released. The bending machine (100; 200) is designed so that when a predetermined release position is reached, the movement of the bending beam (105; 205, 205') towards the predetermined release position actuates the release device (116; 216).

Description

Technical Field

[0001] The invention relates to a bending machine for forming a workpiece by bending. Background Art

[0002] Bending machines, such as, for example, press brakes, are usually designed to operate with different bending tools which, during operation, effect a bending of the respective workpiece.

[0003] The replacement of the bending tool requires opening or closing the corresponding holding device on the bending machine. In the prior art, the known holding device must be opened or closed manually by a human operator. Such manual holding devices require manual labor of the operator and require a long bending tool replacement time.

[0004] Automatic holding devices are also known in the prior art, in which the holding device can be released to remove the bending tool or closed to fix the bending tool by a suitable actuator. For example, hydraulic actuators, pneumatic actuators or electromechanical actuators are used as actuators. Automatic holding devices relieve the burden on human operators, but lead to high manufacturing costs and are prone to errors.

[0005] DE 30 26 847 A1 discloses a press brake in which a bending tool is releasably clamped in a tool holder via an expandable body which can be pressurized hydraulically or pneumatically.

[0006] DE 195 13 576 A1 discloses a bending press having a clamping device for releasably securing a tool, wherein the clamping device is hydraulically actuatable.

[0007] WO 2015 / 164483 A1 describes a tool holder in which a tool is fixed using a clamping device actuated by a cylinder pressurized with compressed air.

[0008] Document US2011 / 247389 A1 discloses a clamping device for clamping a tool in a press brake. The clamping device includes a portion for receiving the tool, an actuating member and an engaging member in contact with the tool. The clamping device is provided with a transmission device arranged between the actuating member and the engaging member. The actuating member can be pneumatically, electrically or hydraulically driven. The transmission device can include a wedge member or a rod.

[0009] Document WO 2020 / 225761 A1 discloses a bending machine for metal sheets, the bending machine comprising a punching device, the punching device comprising an upper tool holding crossbeam. The crossbeam comprises a locking device having a plurality of movable locking elements and configured to engage an upper bending tool and lock the upper bending tool in a locked configuration so as to prevent any movement of the upper bending tool. The locking element is linearly driven between a locked configuration and a released configuration, in which the locking element does not engage and lock the upper bending tool. Summary of the invention

[0010] The object of the present invention is to provide a bending machine having a holding device for a bending tool, wherein the holding device allows automatic fixing and release of the bending tool in a simple manner.

[0011] This object is achieved by the bending machine according to the invention. Other improvements of the invention are defined in other aspects of the invention.

[0012] The bending machine according to the present invention has a bending beam that can be moved in at least one working direction of the bending machine to shape the workpiece by bending along a bending line, wherein the bending line extends in the width direction of the bending machine. The bending machine comprises a holding device for fixing at least one bending tool on the bending machine. A release device is also provided on the bending machine, which, when actuated, transfers the holding device from a closed position in which at least one bending tool is fixed to an open position in which at least one bending tool is released. The bending machine according to the present invention is designed so that when the predetermined release position is reached, the movement of the bending beam towards the predetermined release position actuates the release device.

[0013] The advantage of the bending machine according to the invention is that the movement of the bending beam is not only used for the purpose of bending the workpiece, but also for releasing the bending tool held in the bending machine. In this way, a simple mechanism is created that allows the bending tool on the bending machine to be replaced.

[0014] In a preferred embodiment of the bending machine according to the invention, at least one bending tool is held on the bending beam when the holding device is in the closed position. However, it is also possible that at least one bending tool is held on a bending beam other than the bending beam, the movement of which actuates the release means.

[0015] At least one bending tool can be fixed in different ways depending on the design of the bending machine. In a preferred variant, the holding device arranged in the bending machine is designed to fix the at least one bending tool in a form-fitting and / or non-form-fitting manner. For example, form-fitting fixation can be achieved via sliding control. In the case of non-form-fitting fixation, the holding device applies a holding force to the at least one bending tool to fix the at least one bending tool on the bending machine, wherein, when the release device is actuated, the holding force on the at least one bending tool is terminated, and the holding device thereby enters an open position in which the at least one bending tool is released.

[0016] In another embodiment, the bending machine according to the invention is designed so that when the predetermined release position is reached, the movement of the bending beam generates a release force, which is applied by the release device to the holding device to cancel the fixation of at least one bending tool. This variant of the invention is preferably combined with a form-fitting fixation of at least one bending tool, so that the release force terminates the holding force applied by the holding device to the at least one bending tool.

[0017] In a variation of the embodiment just described, the release means may directly generate the release force by a mechanical action on the holding device. However, the release means may also comprise, for example, a hydraulic circuit which, when the release position is reached, opens and then generates the release force via hydraulic pressure.

[0018] In another preferred embodiment, the bending machine according to the present invention is designed so that the movement of the bending beam towards the predetermined release position is a movement in the working direction of the bending machine. This embodiment is preferably used when the bending machine is a press brake. In a modified embodiment, the movement of the bending beam towards the predetermined release position can also be a movement in a direction deviating from the working direction, wherein the deviation direction preferably corresponds to the width direction of the bending machine. This variant is preferably used when the bending machine is a sheet metal bending machine.

[0019] In another embodiment, the release device is attached to the bending machine in an immovable manner, while the holding device can be moved towards a predetermined release position together with the bending beam. Through this variant, the interaction between the release device and the holding device is realized in a simple manner. The holding device is preferably arranged on the bending beam to hold at least one bending tool on the bending beam, wherein the movement of the bending beam actuates the release device. However, instead of the holding device, the release device can also move with the bending beam, the movement of the bending beam actuates the release device, and the holding device is attached to the bending machine in an immovable manner to hold at least one bending tool on a (stationary) bending beam different from the bending beam, the movement of the bending beam actuating the release device.

[0020] In another variant of the bending machine according to the invention, the release device comprises one or more contact elements, preferably one or more wedges. These contact elements are arranged so that when the predetermined release position is reached, these contact elements mechanically contact the holding device and thereby terminate the fixation of at least one bending tool. With this variant, the release of at least one bending tool can be achieved by a simple mechanical structure. In a preferred embodiment, the application of the holding force generated by the holding device to at least one bending tool is terminated by means of one or more contact elements.

[0021] In a preferred variant, the respective contact element is designed such that, when the predetermined release position is reached, the contact element presses against at least one contact surface of the holding device and in this way triggers a movement of the holding device, whereby the fixation of the at least one bending tool is terminated. Preferably, the application of the holding force generated by the holding device to the at least one bending tool is terminated.

[0022] In another preferred configuration, the holding device is a clamping device, which is designed to exert a holding force in the form of a clamping force on the at least one bending tool to fix the at least one bending tool.

[0023] In another preferred embodiment, the holding device comprises one or more elastic elements, which are pre-tensioned in the holding device to generate a holding force for fixing at least one bending tool. The elastic element can be configured differently, for example, as one or more springs, such as coil springs, and / or as one or more elastomers, etc.

[0024] In order to ensure that the at least one bending tool does not fall out of the holding device when in the open position, in a preferred variant the holding device comprises one or more anti-loss devices to loosely hold the at least one bending tool in the holding device when the holding device is open.

[0025] In order to ensure that at least one bending tool is correctly aligned when being fixed, in another variant, the holding device includes one or more positioning devices to ensure that when a predetermined release position is reached, at least one bending tool moves to a predetermined position, in which the at least one bending tool is held by the holding device.

[0026] In another variant, a sensor system is provided in the bending machine according to the invention, which is configured to detect the approach of the bending beam to the predetermined release position as a detection event. The bending machine is preferably designed so that when a detection event is detected, information is output via a user interface of the bending machine, such as a display. In this way, the operator of the bending machine is informed that the bending machine is in a state where the bending tool can be replaced.

[0027] In another embodiment of the bending machine according to the invention, the release means can be moved into a parking position on the bending machine, in which the release means cannot be actuated by moving the bending beam. In this way, an unintentional loosening of the fixing of at least one bending tool can be prevented.

[0028] In one embodiment, the bending machine according to the invention is a press brake for freely bending a workpiece between a movable upper beam and a fixed lower beam. The bending beam whose movement actuates the release means is the upper beam.

[0029] In a particularly preferred variant of the bending machine designed as a press brake, a holding device is provided on the upper beam for holding the at least one bending tool on the upper beam, wherein the release means is arranged in an immovable manner adjacent to the upper beam and reaches a predetermined release position due to a movement of the upper beam away from the lower beam in the working direction. As a result, the movement of the upper beam, which is already present for bending the workpiece, also serves to release the at least one bending tool in a simple manner.

[0030] In a further embodiment, the bending machine according to the invention is a sheet metal bending machine which is designed in such a way that the workpiece - in contrast to free bending in a press brake - is fixed during the bending.

[0031] In a particularly preferred variant of the bending machine designed as a sheet metal bending machine, a holding device is provided on the bending beam for holding at least one bending tool on the bending beam, wherein the movement of the bending beam actuates the release means, wherein the predetermined release position is located outside the working area of ​​the bending beam in which the bending is performed. In this case, the bending beam can preferably be moved in the width direction of the sheet metal bending machine into the predetermined release position.

[0032] In a preferred embodiment of the above-mentioned sheet bending machine, the sheet bending machine comprises a main bending beam and an auxiliary bending beam, the main bending beam being movable only in the working direction and perpendicular to the plane spanned by the working direction and the width direction, the auxiliary bending beam being a bending beam whose movement actuates the release device, wherein the auxiliary bending beam is arranged on the main bending beam in a movable manner in the width direction. Therefore, the auxiliary bending beam follows the movement of the main bending beam, but can also move relative to the main bending beam in the width direction.

[0033] In a preferred embodiment, the main bending beam comprises one or more bending tools which are firmly connected to the main bending beam and cannot be replaced without additional assistance. In contrast, the corresponding bending tools can be replaced on the secondary bending beam. Thus, when a workpiece must be bent using a specific bending tool, the secondary bending beam is always used as required. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] In the attached picture:

[0036] Figure 1 A first embodiment of a bending machine in the form of a press brake according to the invention is shown in a plan view from the front;

[0037] Figure 2 Shows Figure 1 A three-dimensional diagram of a press brake;

[0038] Figure 3 Shown in plan view from the rear Figure 1 The bending machine in

[0039] Figure 4 and Figure 5 Shows Figure 1 A detailed cross-sectional view of a holding device of a bending machine in a closed state, wherein a bending tool is fixed in the holding device;

[0040] Figure 6 and Figure 7 Shows Figure 1 A detailed cross-sectional view of a holding device of a bending machine in an open state, wherein a bending tool in the holding device is released by a releasing device;

[0041] Figure 8 A perspective view of a second embodiment of a bending machine according to the invention in the form of a sheet metal bending machine is shown;

[0042] Fig. 9 Shown in figure Figure 8 A detailed plan view of a mechanism for moving the auxiliary bending beam in a plate bending machine;

[0043] Fig.10 Shows Figure 1 A detailed view showing the Figure 8 A retaining device and a releasing device for the auxiliary bending beam on the left side of the plate bending machine;

[0044] Fig.11 Shows Fig.10 A plan view of the auxiliary bending beam on the left side of the drawing, wherein the holding device is closed;

[0045] Fig.12 Shown through Fig.10 A cross-sectional view of the auxiliary bending beam on the left side in which the holding device is closed;

[0046] Fig.13 Shows Fig.10 A plan view of the secondary bending beam on the left side of FIG. 1 , with the retaining device opened; and

[0047] Fig.14 Shown through Fig.10 Cross-sectional view of the secondary bending beam on the left side with the retaining device open. DETAILED DESCRIPTION

[0048] In all the figures described below, the spatial orientation of the corresponding bending machine is illustrated by a Cartesian coordinate system with an x-axis, a y-axis and a z-axis. The z-axis represents the height direction, the y-axis represents the width direction in which the bending line of the bending machine extends, and the x-axis represents the direction perpendicular to the y-axis and the z-axis. In the direction of the x-axis, the workpiece to be bent is introduced into the bending machine by an operator or, in some cases, automatically.

[0049] A first embodiment of a bending machine according to the invention in the form of a press brake is described below. Figure 1 is shown in plan view and in Figure 2 1 and is indicated by reference numeral 100. Only the parts of the press brake that are important to the invention are shown.

[0050] The press brake 100 comprises a machine body 101 fixed to the ground, the machine body 101 comprising two side supports 102, 103 and a front plate 104. A fixed lower beam 106 and an upper beam 105 which can be moved in the z direction extend between the side supports 102 and 103 in a manner known per se. In the embodiment described here, the upper beam represents a bending beam within the meaning of the claims. The lower beam 106 has a tool holder 107 on its upper side, to which a suitable lower tool is fastened during operation of the press brake. Similarly, a bending tool is fixed to the lower side of the upper beam 105 for a corresponding bending process, wherein according to Figure 1 and Figure 2 , two such bending tools 109 are provided.

[0051] The press brake 100 is used to bend metal sheets. The metal sheet is introduced along the x-axis into the working area between the lower beam 106 and the upper beam 105, and then the upper beam 105 is moved downward to shape the metal sheet, so that the bending tool 109 presses into the metal sheet and shapes the metal sheet appropriately. The movement of the upper beam 105 is achieved by means of a hydraulic device in the form of two hydraulic cylinders 112, 112', which can be Figure 3 In order to control and monitor the bending process performed by the press brake, a Figure 1 A control device 110 schematically indicated in FIG. 1 and a user interface 111 in the form of a touch display arranged on the front panel 104 in the area of ​​the right side of the press brake.

[0052] Since the forces acting on the sheet during the bending process are high, the corresponding bending tool 109 must be securely fixed in the upper beam 105. However, at the same time it must also be ensured that the bending tool 109 can be replaced. This is ensured by a holding device 113 that fixes the corresponding bending tool 109 to the upper beam 105, wherein the holding device can be opened by means of a release device 116 to remove the bending tool.

[0053] The construction and function of the holding device 113 and the release device 116 are described below with reference to Figures 3 to 7 Explain in more detail. Figure 3 The press brake 100 is shown in a plan view from the rear. Figure 3 The hydraulic cylinders 112 and 112 ′ already mentioned are shown, which act in a manner known per se on the edge region of the upper beam 105 and thus move the upper beam upwards or downwards. Figure 3 Also shown is the above-mentioned holding device 113, which is designed as a clamping device in the embodiment described here. The holding device 113 comprises a clamping plate 114, which extends along the width direction y of the press brake and exerts a clamping force in the x-axis direction on the bending tool 109 in the closed state. The clamping plate is held on the lower end of the upper beam 105 by a large number of fastening means 115 in the form of screws. For the sake of clarity, only some of these fastening means are marked with the reference numeral 115.

[0054] The release means 116 for opening the holding device 113 and thus releasing the fixation of the bending tool 109 in the holding device, in the embodiment described here, comprises a total of eight contact elements 117 in the form of corresponding wedges fastened along the y-direction to a transverse strut 118, which in turn is attached to the machine body 101 via fastening means 119 in the form of screws. Thus, the transverse strut located adjacent to the upper beam 105 in the x-direction is arranged in a fixed manner on the press brake 100 and cannot therefore move together with the upper beam. When the upper beam 105 moves upwards, the contact elements 117 penetrate the holding device 113, which has the result that the holding device 113 opens and the clamping of the bending tool 109 is released, as will be described in more detail below.

[0055] Figure 3Also shown is a sensor system 108 which is only indicated schematically. The sensor system detects when the contact element 117 is in a position within the holding device 113 due to the upward movement of the upper beam 105, so that the clamping of the bending tool 109 is released. When this position is detected, corresponding information is generated on the user interface 111, so that the operator knows that the bending tool 109 is now released and can be removed. In the same way, if the sensor system 108 detects that due to the downward movement of the upper beam 105, the contact element 117 has moved so far out of the holding device 113 that the contact element 117 can no longer influence the opening of the holding device 113, and the bending tool 109 is fixed to the upper beam 105, information can be output via the user interface 111. The corresponding information shows the user that the corresponding bending process can now be performed.

[0056] Figure 4 and Figure 5 A cross-sectional view of the holding device 113 in a closed state is shown, wherein Figure 4 The cross section in the xz plane of Figure 3 The bending tool 109 on the left side of the Figure 5 The cross section in the xz plane of Figure 3 The leftmost wedge 117. Figure 4 and Figure 5 As can be seen in FIG, the contact element 117 is fastened to the transverse strut 118 via fastening means in the form of screws 120. At its lower end, the contact element 117 has a wedge-shaped tip which moves into the retaining device 113 to open it, as will be described in more detail further below.

[0057] The holding device 113 comprises a clamping plate 114, which is formed by a front section 114a and a rear section 114b, which are firmly connected to each other, for example via a screw connection. The rear section 114b is arranged in a recess at the lower end of the upper beam 105 and is held there together with the front section 114a on the upper beam 105 via the fastening means 115 already mentioned above. In the embodiment described here, the fastening means 115 is a screw, which extends from an opening in the front section 114a of the clamping plate 114 through a hole in the rear section 114b of the clamping plate 114 into a threaded hole in the upper beam 105. The screw comprises a rear threaded section 115b and a cylindrical section 115a, which is screwed to the upper beam 105 and on which an elastic device 121 is arranged, which in the embodiment described here is formed by a plate area. In addition, the fastening device 115 has a head 115c, which presses against the elastic device 121, so that a pre-tensioning force is generated. This pre-tensioning force presses the rear section 114b of the clamping plate 114 against the bending tool 109, which is accommodated in the gap between the upper beam 105 and the rear section 114b. As a result, the bending tool 109 is fixed in the holding device 113.

[0058] The correct positioning of the bending tool 109 in the holding device 113 is achieved by means of a positioning device 123 in the form of an adjusting wedge, the triangular tip of which engages in a corresponding recess 125 in the bending tool 109. When the holding device 113 is closed, the adjusting wedge slides into the recess 125 and thus ensures that the bending tool 109 is correctly arranged on the upper beam 105. In addition, at the upper end of the bending tool 109 there is an anti-lost device 122 in the form of a tongue or groove, into which an undercut 124 of the bending tool 109 engages. When the holding device 113 is opened, in the holding device 113, the rear section 114a of the clamping plate 114 moves away from the bending tool 109, and the engagement of the anti-lost device 122 in the undercut 124 ensures that the bending tool 109 is stuck on the upper beam 105. Subsequently, the bending tool 109 can be removed manually from the upper beam 105 by an operator via a corresponding tilting movement.

[0059] from Figure 5, it can be seen that in each section of the clamping plate 114 on which the corresponding contact element 117 is positioned, a recess 129 is formed between the front section 114a and the rear section 114b of the clamping plate. In the region of this recess, there is also an opening in the rear clamping plate 114b, into which a contact block 126 with an inclined contact surface 128 is inserted. The contact surface 128 is in contact with the contact element 117. In addition, an inclined contact surface 127 for the contact element 117 is provided on the front section 114a. When the holding device 113 is opened, the contact element 117 is inserted from above into the recess 129, wherein in Figure 4 and Figure 5 In this state, the contact element 117 has not yet been inserted so deeply that the retaining device opens.

[0060] Figure 6 Shown with Figure 4 A similar cross-sectional view with the retaining device 113 open. In the same way, Figure 7 Shown with Figure 5 Similar cross-sectional view, wherein the holding device 113 is opened. To open the holding device 113, Figure 4 and Figure 5 Compared with the upper beam 105, the upper beam 105 is moved upward a little further, so that Figure 4 and Figure 5 The contact element 117 penetrates deeper into the corresponding recess 129. As a result, the clamping plate 114 moves to the right, whereby the elastic means 121 is compressed and the clamping force acting on the bending tool 109 is thereby released. Therefore, the release means generates a release force that resists the clamping force.

[0061] As from Figure 6 and Figure 7 As can be seen in the figure, when the holding device 113 is in the open position, the rear section 114b of the clamping plate 114 no longer presses against the bending tool 109. Therefore, the bending tool 109 is only loosely held on the upper beam 105 by the anti-loss device 122 and can be replaced by the operator. In order to fix the replaced bending tool, the upper beam 105 moves downward again, which means that the contact element 117 moves out of the corresponding recess 129 and the clamping plate 114 presses against the bending tool 109 again via the elastic device 121, thereby fixing the bending tool. Then, the corresponding bending process can be realized by moving the upper beam 105 further downward toward the workpiece located between the upper beam 105 and the lower beam 106.

[0062] Refer to the following Figures 10 to 14 A second embodiment of the bending machine according to the present invention is described. Figure 8The bending machine is denoted by reference numeral 200 in the perspective view of the embodiment of the present invention. The bending machine is a so-called sheet metal bending machine, which is used to bend metal sheets in the same way as a press brake, wherein, unlike a press brake, the metal sheet is fixed during the bending.

[0063] The sheet bending machine 200 comprises a machine body 201 which, among other things, has two side supports 202 and 203. An upper clamping device 230 which can be moved in the vertical direction and a fixed lower clamping device 232 extend between the side supports. A clamping tool 231 is provided at the lower end of the upper clamping device 230. Similarly, a clamping tool 233 is provided at the upper end of the lower clamping device 232. For the bending process, the workpiece or metal sheet to be bent is fixed between the two clamping tools 231 and 233. For this purpose, the upper clamping device 230 is moved downwards so that the workpiece is clamped between the clamping device 231 and the clamping device 233. The movement of the upper clamping device 230 is preferably realized via a hydraulic device, which cannot be seen from the figure.

[0064] A main bending beam 234 and two auxiliary bending beams 205, 205' are arranged in the sheet bending machine 200 for bending the metal sheet fixed between the clamping tool 231 and the clamping tool 233. The corresponding auxiliary bending beams represent bending beams within the meaning of the patent claims. The main bending beam 234 extends along the clamping devices 230 and 232 in the width direction of the sheet bending machine (i.e., the y direction). The upper bending tool 235 and the lower bending tool 236 are permanently attached to the main bending beam, i.e., these bending tools cannot be replaced without additional assistance. The main bending beam 234 can move in the z-direction and the x-direction, and thus the bending tools 235 and 236 can be used to bend the metal sheet fixed between the clamping tool 231 and the clamping tool 233.

[0065] In order to carry out a specific bending process, two auxiliary bending beams 205, 205' are used in the sheet bending machine 200. These bending beams are arranged on the main bending beam 234 and follow the movement of the main bending beam in the x-direction and the z-direction. In addition, the auxiliary bending beams 205, 205' can be moved in the y-direction relative to the main bending beam 234. Corresponding extension sections 237 and 237' in the form of profiles are attached to each side of the main bending beam 234, wherein the auxiliary bending beam 205 can be driven into the extension section 237 and the auxiliary bending beam 205' can be driven into the extension section 237'. According to Figure 8 The auxiliary bending beams 205, 205' are also located in the extension sections 237, 237'. The movement of the auxiliary bending beams 205, 205' relative to the main bending beam 234 is achieved via a belt drive, which includes a rotation drive 240, 240', a deflection roller 241, 241' and a toothed belt 238, 238'. Fig. 9 The structure of the belt drive is explained in more detail.

[0066] In contrast to the main bending beam 234, the corresponding bending tools are fastened to the auxiliary bending beams 205, 205' in a replaceable manner. Figure 8 , the two bending tools 209 are held on the auxiliary bending beam 205 or the auxiliary bending beam 205' via a holding device 213, which will be further described below. In order to bend the metal sheet, the auxiliary bending beam 205 or 205' can be moved into the main bending beam 234 through the extension section 237 or 237'. The movement of the main bending beam 234 can then cause the corresponding auxiliary bending beam to also move and the bending tool 209 to interact with the metal sheet. After the bending process is completed, the used auxiliary bending beam is moved back into the extension section 237 or 237'. When the corresponding auxiliary bending beam 205, 205' is moved into a specific tool change position within the extension section 237, 237', the release device 216 (see Fig.10 ) interacts with the holding device 213, thereby releasing the bending tool 209 from the holding device 213, as described in more detail below.

[0067] Fig. 9 The structure of the main bending beam 234 and the secondary bending beams 205, 205' is shown in a plan view from the front. In order to move the secondary bending beam 205 from the corresponding extension section 237 into the main bending beam 234, an upper rotary drive 240 is used, which drives a toothed belt 238, which is deflected via a deflection roller 241 and guided back to the rotary drive 240. The secondary bending beam 205 is connected to the toothed belt 238, so that the movement of the toothed belt via the rotary drive 240 causes the movement of the secondary bending beam in the y-direction. Similarly, a lower rotary drive 240' is provided for moving the secondary bending beam 205', which is deflected back to the rotary drive 240' via a deflection roller 241'. The toothed belt 238' is connected to the secondary bending beam 205', so that the movement of the toothed belt causes the movement of the secondary bending beam 205' in the y-direction. Two guide rails 250 are provided for the movement of the bending beams 205 and 205 ′, which extend over the length of the main bending beam 234 and the two extension sections 237 , 237 ′.

[0068] Fig.10 Shows Figure 8 Detailed perspective view of the area of ​​the auxiliary bending beam 205 on the left in FIG. As can be seen, the auxiliary bending beam 205 has a U-shaped profile, which merges into a corresponding U-shaped profile of the extension section 237. The auxiliary bending beam 205 is slidably guided along guide rails 250 via two upper and two lower guide brackets 249 (see FIG. Figures 11 to 14 ). Fig.10 Also shown are two holding devices 213 (an upper and a lower holding device) provided for the secondary bending beam 205 , each of the two holding devices 213 comprising a front clamping rod 243 via which the bending tool is clamped to the secondary bending beam 205 .

[0069] In addition, for both retaining devices 213, a release device 216 which is not visible per se and opens the corresponding retaining device is shown in dashed lines. The release device for the upper retaining device comprises two contact elements 217 in the form of wedges, which are fastened and in particular screwed to the lower side of the upper leg of the extension section 237. In addition, a wedge strip 242 is provided, which is arranged in a movably manner between the upper leg of the extension section 237 and the upper leg of the bending beam 205. The wedge strip 242 interacts with the contact elements 217, as will be described further below. A corresponding contact element 217 in the form of a wedge is also arranged on the upper side of the lower leg of the extension section 237, which in turn interacts with the wedge strip 242 arranged in a movably manner between the lower leg of the extension section 237 and the lower leg of the bending beam 205.

[0070] Fig.11 and Fig.12 The structure of the upper holding device 213 and the associated release means 216 of the bending beam 205 are shown in detail in a state in which the bending tool 209 is fixed by the holding device 213 . Fig.11 A plan view of the plane in which the two contact elements 217 and the wedge strip 242 for the upper holding device are located is shown. The secondary bending beam 205 is in a position outside the main bending beam 234, but does not yet correspond to the Fig.11 The release position further to the left in the figure, in which the retaining device 213 is opened. Fig.11 As can be seen in FIG. 1 , the wedge strip 242 has two inclined contact surfaces 227. Fig.11 In the position shown in FIG. 2 , the two inclined contact surfaces 227 do not yet interact with the opposite inclined surfaces of the contact element 217. In addition to the front clamping rod 243, Fig.11 Also shown are a plurality of fastening means 244 in the form of screws, a plurality of elastic means 221 in the form of coil springs, a rear clamping rod 247 and further fastening means 246. Fig.12 Describe these components.

[0071] Fig.12 Shows Fig.11209 in the section in the xz plane at the location of the bending tool 209. As can be seen, the fastening means 244 is screwed to a retaining means 245 in the form of a cylindrical pin, which in turn is inserted into a hole in the wedge strip 242 and thereby produces a rigid connection between the wedge strip 242 and the retaining means 245 via a further fastening means 246. The retaining means 245 holds the wedge strip 242 between the upper leg of the extension section 237 and the lower leg of the bending beam 205. In addition, in Fig.12 As can be seen in the figure, the rear clamping rod 247 is located behind the front clamping rod 243 and is firmly connected to the upper leg of the bending beam 205, for example via a screw connection. The rear clamping rod 247 has a hole with a socket 248, through which the holding element 248 extends. The socket and a section on the back of the rear clamping rod 247 press against the elastic element 221 in the form of a disc spring. The section of the elastic element 221 is arranged in the receiving part of the clamping rod 242, so that the clamping rod 242 constitutes a support for the elastic element 221 placed under pretensioning force.

[0072] exist Fig.12 In the embodiment, the distance between the front clamping rod 243 and the rear clamping rod 242 is so small that the bending tool 209 is clamped between the two clamping rods. Similarly to the first embodiment described above, a positioning device 223 in the form of an adjustment wedge is provided again, which engages in a corresponding recess 225 of the bending tool 209. In addition, just as in the first embodiment, a loss prevention device 222 in the form of a tongue or groove is provided, into which an undercut 224 of the bending tool 209 engages.

[0073] In order to release the fixation of the bending tool 209 in the holding device 213, the auxiliary bending beam 205 is moved further to the left in the y direction until it reaches Fig.13 and Fig.14 Release position shown in . Fig.13 Shown with Fig.11 Similar floor plans, and Fig.14 Shown with Fig.12 Similar cross-section. Fig.13 As can be seen in FIG. 2 , when the release position is reached, the front inclined section of the corresponding contact element 217 interacts with the oppositely inclined contact surface 227 of the wedge strip 242. As a result, under the compression of the elastic means 221, the wedge strip 242 slides forward together with the retaining means 245 and the front clamping rod 243 (i.e., in Fig.14The front clamping rod 243 is slid to the right in the cross-sectional view of FIG. 21 ), thereby increasing the distance between the front clamping rod 243 and the rear clamping rod 247 and thereby releasing the clamping of the bending tool 209 in the holding device 213. The bending tool 209 is still held in the holding device via the anti-loss device 222, but can be removed from the holding device by the operator via a corresponding tilting movement.

[0074] An embodiment of a bending machine has been described above in which the fixing of the bending tool in the corresponding holding device is ensured via elastic means and this fixing is released in a purely mechanical manner by generating a corresponding release force. However, the bending tool can also be fixed in some other way, for example hydraulically, and the corresponding release force for releasing this fixing can also be generated hydraulically.

[0075] If hydraulic clamping is used instead of mechanical clamping in the above-mentioned sheet bending machines, this has the disadvantage that hydraulic hoses must be laid over the entire bending length, for example via hydraulic hoses of an energy chain. In order to avoid this disadvantage, a hydraulic clamping rod with a closed hydraulic circuit can be used. The auxiliary bending beam has two positions, a parking position and a tool change position. The bending tool is still clamped in the parking position, while this clamping is released in the tool change position. In the tool change position, the quick-release coupling of the otherwise self-sufficient hydraulic circuit of the clamp is connected to the controlled circuit and the pressure of the clamp for disengaging or clamping the bending tool is directly controlled. A hydraulic pump can also be provided for this purpose.

[0076] If the auxiliary bending beam is in the parking position, the hydraulic pressure in the self-sufficient hydraulic circuit is constant and the bending tool is held in the clamping unit. There is no connection to the controlled hydraulic circuit. If the auxiliary bending beam is moved to the tool change position, it is connected to the controllable hydraulic circuit via a quick coupling. The hydraulic pressure in the controlled hydraulic circuit can then be reduced, thereby achieving a release of the clamp. On the other hand, the pressure for achieving clamping is increased again. If, after a tool change, the auxiliary bending beam is subsequently moved from the tool change position to the parking position, the controllable hydraulic circuit is disconnected again, wherein the non-return valve keeps the pressure in the clamp constant. The clamping then becomes self-sufficient again.

[0077] The embodiments of the invention described above offer numerous advantages. In particular, the already existing movement of the bending beam in the bending machine can also be used in a simple manner to open the holding device and thereby release the bending tool fixed in the holding device. A release position of the movable bending beam is defined, wherein, when the release position is reached, the movement of the bending beam towards the release position actuates a corresponding release device and thereby opens the holding device. The invention can be used for various types of bending machines. In particular, the invention can be used both for press brakes in which workpieces are freely bent and for sheet metal bending machines in which the workpieces are fixed during the bending process.

[0078] Reference numerals

[0079] 100 Bending machine (press bending machine)

[0080] 101 Machine body

[0081] 102,103 side bracket

[0082] 104 front panel

[0083] 105 bending beam (upper beam)

[0084] 106 Lower beam

[0085] 107 Tool Holder

[0086] 108 sensor system

[0087] 109 Bending tools

[0088] 110 Control Device

[0089] 111 User interface (display)

[0090] 112,112' hydraulic cylinder

[0091] 113 holding device (clamping device)

[0092] 114 Clamping plate

[0093] 114a Front section of 114

[0094] 114b The rear section of 114

[0095] 115 Fastening device (screw) for 114

[0096] 115a The cylindrical section of 115

[0097] 115b Threaded section of 115

[0098] 115c 115 head

[0099] 116 Release device

[0100] 117 contact element (wedge)

[0101] 118 lateral support

[0102] 119 Fastening device (screw) for 118

[0103] 120 Fastening device (screw) for 117

[0104] 121 elastic device (coil spring)

[0105] 122 Anti-loss device (spring)

[0106] 123 positioning device (adjusting wedge)

[0107] 124 Undercut

[0108] 125 recess

[0109] 126 contact block

[0110] 127 114a bearing surface

[0111] 128 126 contact area

[0112] 129 Concave

[0113] 200 bending machine (plate bending machine)

[0114] 201 Machine body

[0115] 202,203 side bracket

[0116] 205 bending beam (secondary bending beam)

[0117] 205' bending beam (auxiliary bending beam)

[0118] 209 bending tool

[0119] 213 holding device (clamping device)

[0120] 216 Release Device

[0121] 217 contact element (wedge)

[0122] 221 elastic device (coil spring)

[0123] 222 Anti-loss device (spring)

[0124] 223 positioning device (adjusting wedge)

[0125] 224 Undercut

[0126] 225 concavity

[0127] 227 242 contact surface

[0128] 230 upper clamping device

[0129] 231 clamping tool

[0130] 232 Lower clamping device

[0131] 233 clamping tool

[0132] 234 Main bending beam

[0133] 235 upper bending tool

[0134] 236 lower bending tool

[0135] 237,237' extension section

[0136] 238,238' toothed belt

[0137] 240,240' rotary drive

[0138] 241,241' deflection roller

[0139] 242 wedge strip

[0140] 243 front clamping rod

[0141] 244 Fastening device (screw) for 243

[0142] 245 Retaining device for 242 (cylindrical pin)

[0143] 246 Fastening device for 242

[0144] 247' rear clamping bar

[0145] 248 sockets

[0146] 249 guide bracket

[0147] 250 Guide Track

Claims

1. A bending machine (100; 200) having a bending beam (105; 205, 205'), the bending beam (105; 205, 205') being movable in at least one working direction (z) of the bending machine (100; 200) to shape a workpiece by bending along a bending line extending in a width direction (y) of the bending machine (100; 200), the bending machine (100; 200) comprising a holding device (113; 213) and a release device (116; 216), the holding device (113; 213) is used to install at least one bending tool (109; 209) on the bending machine (100; 200), the releasing device (116; 216) is arranged on the bending machine (100; 200) to move the holding device (113; 213) from a closed position in which the at least one bending tool (109; 209) is fixed to an open position in which the at least one bending tool (109; 209) is released, It is characterized in that The bending machine (100; 200) is designed such that, when a predetermined release position is reached, the movement of the bending beam (105; 205, 205') towards the predetermined release position actuates the release means (116; 216).

2. The bending machine according to claim 1, characterized in that: The holding device (113; 213) is designed to fix the at least one bending tool (109; 209) in a form-fitting and / or non-form-fitting manner.

3. The bending machine according to claim 1 or 2, characterized in that: The bending machine (100; 200) is designed so that when the predetermined release position is reached, the movement of the bending beam (105; 205, 205') generates a release force, and the release force is applied to the holding device (113; 213) by means of the release device (116; 216) to cancel the fixation of the at least one bending tool (109; 209).

4. The bending machine according to claim 1 or 2, characterized in that: The bending machine (100; 200) is designed so that the movement of the bending beam (105; 205, 205') towards the predetermined release position involves movement along the working direction (z) or along a direction deviating from the working direction (z), wherein the deviating direction corresponds to the width direction (y) of the bending machine (100; 200).

5. The bending machine according to claim 1 or 2, characterized in that: The release device (116; 216) is attached to the bending machine (100; 200) in an immovable manner, and the holding device (113; 213) is movable toward the predetermined release position together with the bending beam (105; 205, 205'), wherein the holding device (113; 213) is arranged on the bending beam (105; 205, 205') to hold the at least one bending tool (109; 209) on the bending beam (105; 205, 205').

6. The bending machine according to claim 1 or 2, characterized in that: The release device (116; 216) comprises one or more contact elements (117; 217), which are arranged so that when the predetermined release position is mechanically contacted, the contact element releases the holding device (113; 213) and thereby terminates the fixation of the at least one bending tool (109; 209).

7. The bending machine according to claim 6, characterized in that: The corresponding contact element (117; 217) is designed so that when the contact element (117; 217) reaches the predetermined release position, the contact element (117; 217) presses against at least one contact surface (127; 227) of the holding device (113; 213) and thereby triggers the movement of the holding device (113; 213), which results in the fixation of the at least one bending tool (109; 209) being terminated.

8. The bending machine according to claim 1 or 2, characterized in that: The holding device (113; 213) is a clamping device, which is designed so that in order to fix the at least one bending tool (109; 209), the clamping device applies a holding force in the form of a clamping force to the at least one bending tool (109; 209).

9. The bending machine according to claim 1 or 2, characterized in that: The holding device (113; 213) comprises one or more elastic elements (121; 221), wherein the elastic elements (121; 221) are pre-tensioned in the holding device (113; 213), thereby generating a holding force for fixing the at least one bending tool (109; 209).

10. The bending machine according to claim 1 or 2, characterized in that: The holding device (113; 213) comprises: one or more anti-loss devices (122; 222), wherein the one or more anti-loss devices (122; 222) are used to loosely hold the at least one bending tool (109; 209) in the holding device (113; 213) when the holding device (113; 213) is opened; and / or one or more positioning devices (123; 223), wherein the one or more positioning devices (123; 223) are used to ensure that when the predetermined release position is reached, the at least one bending tool (109; 209) moves to a predetermined position, in which the at least one bending tool (109; 209) is held by the holding device (113; 213).

11. The bending machine according to claim 1 or 2, characterized in that: A sensor system (108) is provided in the bending machine (100; 200), and the sensor system (108) is configured to detect the approach of the bending beam (105; 205, 205') to the predetermined release position as a detection event, wherein the bending machine (100; 200) is configured to output information via a user interface (111) of the bending machine (100; 200) when the detection event is detected.

12. The bending machine according to claim 1 or 2, characterized in that: The release device (116; 216) can be moved into a parking position on the bending machine, in which the release device (116; 216) cannot be actuated by moving the bending beam (105; 205, 205').

13. The bending machine according to claim 1 or 2, characterized in that: The bending machine (100; 200) is a press brake (100) for freely bending a workpiece between a movable upper beam (105) and a fixed lower beam (106), wherein the bending beam (105; 205, 205') is the upper beam (105).

14. The bending machine according to claim 13, characterized in that: The holding device (113; 213) is arranged on the upper beam (105) to hold the at least one bending tool (109; 209) on the upper beam (105), and the releasing device (116; 216) is arranged to be adjacent to the upper beam (105) in an immovable manner, wherein the predetermined release position is reached by moving the upper beam (105) away from the lower beam (106) along the working direction (z).

15. The bending machine according to claim 1 or 2, characterized in that: The bending machine (100; 200) is a sheet metal bending machine (200) which is configured such that the workpiece is fixed during bending.

16. The bending machine according to claim 15, characterized in that: The holding device (113; 213) is arranged on the bending beam (105; 205, 205') to hold the at least one bending tool (109; 209) on the bending beam (105; 205, 205'), and the predetermined release position is located outside the working area where the bending beam (105; 205, 205') performs bending, wherein the bending beam (105; 205, 205') can be moved to the predetermined release position along the width direction (y) of the sheet metal bending machine (200).

17. The bending machine according to claim 6, characterized in that: The one or more contact elements (117; 217) are one or more wedges.

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