A clamping system for a press brake with two interconnected cavities, a press brake with the clamping system, and a method for manufacturing an elongated beam for the clamping system.

Abstract

This invention relates to a clamping system for press brakes. [Solution] The clamping system comprises an elongated beam including a receiving space for receiving a portion of a bending tool, the elongated beam having at least two cavities formed therein, each of the at least two cavities having an opening to the outside of the elongated beam. The clamping system is characterized in that the at least two cavities are interconnected internally. The present invention also relates to a press brake comprising such a clamping system, and a method for manufacturing an elongated beam for such a clamping system. The method includes, among other things, the step of providing a fluid connection to each of the at least two cavities in the elongated beam by mechanically interconnecting the at least two cavities from the inside of at least one of the at least two cavities.

Description

Technical Field

[0001] The present invention relates to a clamping system for a press brake, the clamping system comprising an elongate beam having a receiving space for receiving a part of a bending tool, the elongate beam having at least two cavities formed therein, each of the at least two cavities having an opening to the outside of the elongate beam.

[0002] A press brake is a machine used for bending or folding sheet materials such as metal sheets. For this purpose, a press brake includes a bottom beam and a top beam movable relative to each other. Both the top beam and the bottom beam hold tools, and a workpiece is provided therebetween for bending. Generally, the bending tools of a press brake are replaceable, can make different types of bends or folds, and the tools can be inspected. Therefore, a press brake comprises a clamping system that can releasably clamp the tools. The clamping system can be provided on the top beam, the bottom beam, or both, of the press brake.

[0003] There are two types of press brakes. The first type has a clamping system that is an integral part of either the top beam or the bottom beam. An additional clamping system may or may not be provided on the other of the top or bottom beam. The integrated clamping system cannot be removed from its top or bottom beam and therefore cannot be replaced by another clamping system itself, but the tools that the clamping system can hold are interchangeable. The second type has a replaceable clamping system that can be connected to and fixed to either the top beam or the bottom beam. An additional clamping system may or may not be provided on the other of the top or bottom beam. The replaceable clamping system allows for tool replacement but can also be removed from the top or bottom beam, for example, for maintenance or to be replaced with another clamping system. This is a technique used to make one press brake suitable for different tool types that may require different clamping systems, and / or to inspect the clamping system.

[0004] There exist further clamping systems that can be clamped by other clamping systems as if they were tools. Such clamping systems can be clamped by, for example, a first type of tooling system, but can also clamp a second type of tool itself, thus acting as adapters between clamping systems and tools that would otherwise be incompatible.

[0005] The present invention relates to a clamping system integrated with a press brake, a replaceable clamping system, and a clamping system acting as an adapter, whether for a bottom beam or a top beam, and to a method for making an elongated beam for such a clamping system.

[0006] Press brakes and clamping systems thereof are known, for example, from the applicant's earlier application WO 2010 / 056110 A1, which describes a clamping device for clamping a tool. The clamping device includes an operating member and an engaging member. The operating member is driven, for example, by hydraulic or pneumatic means.

[0007] The clamping device disclosed in WO 2010 / 056110 A1 is fully functional and still works today, but there is a need for further improvement of the clamping device. This need exists particularly in terms of improving reliability and ease of manufacture. [Overview of the project]

[0008] Therefore, the present invention aims to provide a clamping system that is more reliable and relatively easy to manufacture.

[0009] According to the present invention, this objective is achieved by the clamping system for press brakes described in the preamble, characterized in that at least two cavities are interconnected internally.

[0010] Cavities within elongated beams can be used to house drive means for operating a clamping system, such as a piston. In particular, each cavity can house a piston for a hydraulic or pneumatic operating system, which preferably acts directly on the clamping element to engage a tool in the receiving space of the elongated beam. The clamping element may be movable between a first position in which it can engage a bending tool for clamping within the receiving space and a second position for releasing the bending tool. Thus, the piston can constitute an operating member.

[0011] The cavities are expected to extend parallel to each other and at a distance from one another, as seen along the length of an elongated beam. Therefore, multiple drive mechanisms can be arranged along the length of the elongated beam to clamp multiple tools, or to clamp tools at multiple positions.

[0012] Since multiple drive mechanisms or their components are housed within multiple cavities, the cavities need to be interconnected. By connecting the cavities internally, there is no need to provide external interconnects for the two connections. Therefore, the additional manufacturing effort required to provide external interconnects is no longer necessary. Furthermore, external connections, which may include, for example, conduits or wiring, are prone to failure because they are exposed to external factors. Moreover, the connection points between elongated beams and external interconnects are prone to damage or failure, or may require periodic inspection. Therefore, by providing internal interconnects, the clamping system is less susceptible to failure and thus more reliable. Consequently, fewer inspections are required.

[0013] In particular, when a conduit carries a hydraulic or pneumatic fluid, it takes a relatively long time for the fluid to move through the conduit, and the conduit imposes relatively high resistance on the fluid. Therefore, by providing the internal connection, the time and / or pressure required to move the hydraulic or pneumatic fluid is reduced, thereby allowing the clamping element to move more quickly. This allows the tool to be released and / or replaced more quickly.

[0014] Furthermore, the cavity may be used directly as a pneumatic or hydraulic pressure chamber by inserting a piston into the cavity, for example, as described below.

[0015] Additionally or alternatively, the manufacture of the clamp system is relatively easy because it provides additional components for external connection and does not require installation.

[0016] Here, "interior" refers to the inside of the slender beam. Here, "exterior" refers to the outside of the slender beam.

[0017] The two cavities may be formed integrally within the elongated beam, in contrast to being formed within a separate body fixed to the elongated beam.

[0018] This offers the advantage of eliminating the need for a separate body and the subsequent need to fix and / or seal it to the elongated beam. Thus, the clamping system is simplified, thereby eliminating potential points of failure and simplifying the manufacturing process. Furthermore, a separate body introduces an additional source of error when positioning the press brake components relative to each other, particularly when positioning the cavity relative to the clamping element.

[0019] Additionally, or alternatively, by integrally forming at least two cavities within the elongated beam, the clamp system can be manufactured relatively cost-effectively.

[0020] The interconnection may be provided as a channel between at least two cavities cut from a slender beam material.

[0021] In one embodiment of the clamping system, the clamping system further includes a channel extending from at least one of at least two cavities to the outside of the elongated beam.

[0022] The channel may be used, for example, to supply appropriate input and / or output to a cavity or components within it by continuing conduits and / or wiring through the channel. In particular, the channel itself can form a conduit through which a fluid can flow to at least one of at least two cavities. Such a fluid may be a hydraulic fluid or a pneumatic fluid.

[0023] The other of the at least two cavities may have the same input and / or output via an interconnection with at least one of the at least two cavities.

[0024] In another embodiment of the clamping system, at least two cavities are interconnected via their respective side walls.

[0025] Providing an interconnecting portion on the side wall is helpful for maintaining the structural rigidity of the elongated beam because there is less material of the elongated beam that needs to be removed to form the interconnecting portion through the side wall. In particular, since the cavities are arranged adjacent to each other and their respective side walls face each other, it is beneficial for maintaining the structural rigidity of the elongated beam. Also, as will be described later, wiring can be provided on the side wall relatively easily.

[0026] In yet another embodiment of the clamping system, at least two cavities are interconnected in an end zone of the cavity that faces the opening of each cavity.

[0027] In this embodiment, since the openings are left free, for example, the drive means within the cavity can be used for engaging with the actuating member of the clamping system. By installing the interconnecting portion away from the opening, the drive means can be input and output through the interconnecting portion without hindering the operation of the drive means.

[0028] In yet another embodiment of the clamping system, the clamping system further comprises a cylinder in each of at least two cavities.

[0029] The cylinder can be used as part of a pneumatic or hydraulic pressure for driving the clamping system, for example, to drive the actuating member of the clamping system.

[0030] The cylinder can be supplied with pneumatic or hydraulic fluid through the interconnecting portion between the cavities and / or a channel. For this purpose, the pneumatic fluid or hydraulic fluid can flow directly through the interconnecting portion and / or the channel, or a conduit through which the fluid flows through the interconnecting portion and / or the channel may be provided.

[0031] In yet another embodiment of the clamping system, the clamping system further comprises a piston in each of at least two cavities or in each cylinder of at least two cavities.

[0032] The piston can be used as part of a pneumatic or hydraulic system to drive a clamping system, for example, to drive the working member of the clamping system. The piston may be movable within a cylinder in a cavity and configured to cooperate with it, or the piston may be directly movable within a cavity and configured to cooperate with it. In the latter case, the cavity itself can act as a cylinder to cooperate with the piston. In this case, no conduit is needed, as air or hydraulic fluid can flow between the two cavities through an interconnection between the two cavities.

[0033] The present invention also relates to a press brake comprising at least one clamping system as described above. The clamping system may have any of the above features individually or in any suitable combination.

[0034] The clamping system can be located within the top beam of the press brake, within the bottom beam of the press brake, or both. The clamping system may be a separate, replaceable clamping system, often referred to in the art as a clamping beam, or it may be an integral part of the press brake.

[0035] Furthermore, the present invention relates to a method for manufacturing an elongated beam for a clamping system for a press brake, wherein the elongated beam has a receiving space for receiving a portion of a bending tool, and the method is a) A step of providing a long, slender beam, b) A step of forming at least two cavities within an elongated beam, each of which has an opening to the outside of the elongated beam, c) Providing a fluid connection to each of at least two cavities, Includes, The step of providing a fluid connection is characterized by interconnecting at least two cavities by inserting a tool through the opening of at least one of the at least two cavities and machining toward the other of the at least two cavities.

[0036] According to this method, interconnections between at least two cavities are provided from the inside of one cavity toward the other. In this way, interconnections can be provided inside an elongated beam. As a result, at least two cavities can be interconnected internally. This has the advantages mentioned above with respect to the clamping system.

[0037] This method can be used to manufacture elongated beams for use in clamping systems as described above, and can, in itself, include the features described above, either individually or in any suitable combination.

[0038] In one embodiment of this method, step c) is performed by machining from one of the at least two cavities until one of the at least two cavities is interconnected with the other of the at least two cavities.

[0039] In this embodiment, machining from one cavity to another is performed in a single direction. Therefore, once the means for machining are set up within one cavity, machining can continue until the interconnection is complete. This helps to provide an efficient interconnection. Furthermore, since there is no need to provide means for machining in the opposite direction to the other cavity, the total time required to set up the means for machining is reduced.

[0040] Furthermore, compared to an alternative where the interconnection is provided by machining from both cavities toward the other, it is not necessary to align the machining direction from each cavity and to adjust the machining depth relative to each other.

[0041] In another embodiment of this method, the method further includes the step of forming a channel from at least one of at least two cavities to the outside of the elongated beam.

[0042] In yet another embodiment of this method, the method further includes the step of providing interconnections to the side walls of at least two cavities.

[0043] In yet another embodiment of this method, the method further includes the step of providing interconnections in the end zones facing the openings of each cavity.

[0044] In yet another embodiment of this method, the method further includes the step of inserting a cylinder into each of at least two cavities.

[0045] In yet another embodiment of this method, the method further includes the step of inserting a piston into each of at least two cavities or into a cylinder inserted therein.

[0046] In yet another embodiment of this method, the method includes the steps of inserting a tool in the insertion direction and moving the tool continuously in the machining direction, where the machining direction is at a non-zero angle with respect to the insertion direction, and preferably the machining direction is substantially perpendicular to the insertion direction.

[0047] Therefore, interconnections can be provided, for example, near the side walls of the cavity and / or the end zones removed from the opening of the cavity. The interconnections can extend laterally away from the cavity, and as a result, adjacent cavities can be interconnected with their respective side walls facing each other, as in the case of cavities arranged parallel to each other.

[0048] In yet another embodiment of this method, the tool comprises a shaft and a head, the head having a larger cross-sectional dimension than the shaft.

[0049] Using such tools helps to avoid damaging the side walls of the cavity during machining.

[0050] In yet another embodiment of this method, step c) is performed by milling. A suitable milling tool can be used for this purpose.

[0051] The applicant found that appropriate interconnections between cavities can be provided internally by milling.

[0052] In yet another embodiment of this method, step b) is performed by milling or drilling.

[0053] The applicant found that suitable channels can be formed by milling or drilling. Channels can be formed, for example, by drilling from the outside of an elongated beam towards a cavity within it.

[0054] In yet another embodiment of this method, the method further includes the step in step b) forming a cavity in a portion of an elongated beam that is integral with a portion of an elongated beam having a receiving space.

[0055] To the applicant's knowledge, press brakes have historically had a cavity located within a separate body fixed to an elongated beam. This not only necessitates securely fixing the separate body to the elongated beam, but often also requires proper sealing of the separate body to the elongated beam. Even when appropriate fixing and sealing techniques exist, both fixing and sealing remain potential points of failure and therefore must be regularly inspected and / or examined to avoid failure or damage to the clamping system. By integrally forming the cavity within the elongated beam, a separate body is not required. Therefore, there is no fixing and / or sealing of such a body that could constitute a failure. Thus, the clamping system can operate more reliably and / or require less inspection and / or examination. [Brief explanation of the drawing]

[0056] The present invention will be further described below with reference to the attached drawings. [Figure 1A] Figure 1A schematically shows a cross-sectional side view of a press brake with a replaceable clamping system. [Figure 1B] Figure 1B schematically shows a front view of a press brake with a replaceable clamping system. [Figure 2A] Figure 2A schematically shows a cross-sectional side view of a press brake equipped with an integrated clamping system. [Figure 2B] Figure 2B schematically shows a front view of a press brake equipped with an integrated clamping system. [Figure 3A] Figure 3A shows a schematic perspective cross-sectional view of the clamping system and tools. [Figure 3B] Figure 3B shows a schematic cross-sectional view of the clamping system and tools. [Figure 3C] Figure 3C shows a schematic cross-sectional view of the clamping system and tools. [Figure 4A] Figure 4A schematically shows a perspective view of the slender beam of the clamping system shown in Figures 3A-3C. [Figure 4B] Figure 4B schematically shows a perspective view of the slender beam of the clamping system shown in Figures 3A-3C. [Figure 5] Figure 5 schematically shows a modified version of the clamp system shown in Figures 3A-5. [Figure 6] Figure 6 schematically shows a modified version of the clamp system shown in Figures 3A-5. [Figure 7A] Figure 7A schematically shows another clamping system and tool in a perspective view. [Figure 7B] Figure 7B schematically shows another clamping system and tool in a side view. [Figure 7C] Figure 7C schematically shows another clamping system and tool in a side view. [Figure 8] Figure 8 schematically shows a modified version of the clamp system shown in Figures 7A-7C. [Figure 9] Figure 9 schematically shows a cross-sectional view of yet another clamping system. [Figure 10A]Figure 10A schematically shows a perspective view of the elongated beam of the clamping system in Figure 9. [Figure 10B] Figure 10B schematically shows the longitudinal section of the slender beam of the clamping system in Figure 9. [Figure 11A] Figure 11A shows schematic steps in a method for interconnecting cavities within a long, slender beam. [Figure 11B] Figure 11B shows schematic steps in a method for interconnecting cavities within a long, narrow beam. [Figure 11C] Figure 11C shows schematic steps in a method for interconnecting cavities within an elongated beam. [Figure 11D] Figure 11D shows schematic steps in a method for interconnecting cavities within an elongated beam. [Figure 12] Figure 12 schematically shows a modified version of the clamping system in Figure 5. Detailed explanation

[0057] Figures 3B, 3C, 5, 6, 7B, 7C, 8, 9, and 12 show views from the same side as Figures 1A and 2A.

[0058] In the diagram, similar elements are given the same reference numeral. Corresponding elements in different embodiments are referenced with reference numerals that are incremented by multiples of 100.

[0059] Figures 1A and 1B show a press brake 1 installed on a ground surface G. The press brake 1 includes a top beam 2 and a bottom beam 3. The top beam 2 is provided with a top clamping system 4. The clamping system removably holds a top tool 5. The bottom beam 3 is provided with a bottom clamping system 6 that removably holds a bottom tool 7. The top beam 2 and bottom beam 3 are movable toward and away from each other by a hydraulic system 8. Thus, the top tool 5 and bottom tool 7 are also movable toward and away from each other. To bend sheet metal, the sheet is inserted between tools 5 and 7, and then they are moved toward each other. Next, the top tool 5 pushes the sheet metal into the bottom tool 7 to bend and deform the sheet metal. After bending, tools 5 and 7 are moved toward each other by moving the top beam 2 via the hydraulic system 8. The clamping systems 4 and 6 are detachably mounted to the top beam 2 and bottom beam 3, respectively, via appropriate locking systems. Therefore, the clamping systems 4 and 6 can be replaced with clamping systems suitable for other tools, or they can be removed for inspection.

[0060] Figures 2A and 2B show a similar press brake 101, and only the differences from the press brake 1 in Figures 1A and 1B are described here. The clamping systems 104 and 106 of the press brake in Figures 2A and 2B are integrated with the top beam 102 and bottom beam 103, respectively. Therefore, the clamping systems 104 and 106 are not interchangeable. The tools 105 and 107 held by the clamping systems 104 and 106 are interchangeable.

[0061] Figures 3A-3C show a clamping system 204 that can be used, for example, in the press brake shown in Figures 1A-2B. The clamping system 204 has an elongated beam 209 as its main body. A receiving space 210 within the elongated beam 209 accommodates a portion of the tool 205. The clamping system further comprises an actuating member 211 and a clamping element 212. The actuating member 211 is movable upward to a non-actuating position and downward to an actuating position. The clamping element 212 is movable between a first position extending into the receiving space 210 to engage with the tool 205 and a second position retracting from the receiving space 210 to release the tool. The clamping element 212 has an engaging tip 213 which cooperates with an engaging recess 214 in the tool 205 to securely clamp the tool 205 into the receiving space 210. In the operating position, the actuator 211 engages with the clamp element 212 and biases it toward the receiving space 210. Figure 3B shows the actuator 211 in the operating position so that the tool 205 is clamped into the receiving space 210 by the clamp element 212. The actuator 211 has an inclined engagement surface 215 for engaging with the clamp element 212, and this inclined engagement surface 215 engages with an inclined engagement surface 216 of the clamp element 212, which also cooperates. Therefore, when the actuator 211 moves to its operating position, i.e., downward in the figure, the engagement surface 215 of the actuator 211 engages with the engagement surface 216 of the clamp element 212, and its inclination presses the clamp element 212 toward its first position (i.e., to the left in the figure). Figure 3C shows the actuator 211 in the non-operating position with the clamp element 212 retracted from the receiving space 210 to a second position, thereby releasing the tool 205.

[0062] The actuating member 211 is movably positioned within the pressure chamber 217. The pressure chamber 217 is formed directly within the elongated beam 209, which also has a receiving space 210. Thus, the pressure chamber 217 is integrally formed within the elongated beam 209. The actuating member 211 is provided with sealing means 218 that seal the actuating member 211 against the wall of the pressure chamber 217, i.e., the inside of the elongated beam 209. In this way, the actuating member 211 functions as a movable piston within the pressure chamber 217, and therefore the piston functions as a cylinder. Thus, the actuating member 211 can be pushed toward its operating position by introducing fluid into the pressure chamber 217. The pressure chamber 217 of this clamp system 204 is configured to receive a hydraulic fluid as a pressurized fluid in order to move the actuating member 211.

[0063] The clamping system 204 includes a first biasing member in the form of a first compression spring 219. The first compression spring acts on the actuating member 211. The first compression spring 219 is positioned perpendicular to the pressing direction P defined by the clamping mechanism 204 and the depth direction of the receiving space 210. The first compression spring 219 biases the actuating member 211 upward, i.e., toward its non-acting position. Thus, when the pressure of the working fluid in the pressure chamber 217 is stopped, the first compression spring 219 pushes the actuating member 211 further into the pressure chamber 217, forcing the working fluid to flow out of the pressure chamber 217. The first compression spring 219 is supported on a support 220 provided by a cover 221. The cover 221 covers the clamping element 212, the actuating member 211, and the pressure chamber 217. The cover 221 also forms a first stopper 222 against which the actuator 211 abuts to restrict the actuator 211 from moving beyond its operating position. The actuator 211 has a movement limiter 223 for engaging with the first stopper 222. A first compression spring 219 partially extends into a first cavity 224 within the actuator 211. A second biasing member is provided in the form of a second compression spring 225. The second compression spring 225 is positioned horizontally, i.e., perpendicular to the pressing direction P and the longitudinal direction of the elongated beam 204. The second compression spring 225 acts on the clamp element 104 via a projection 226 of the clamp element 212, while the first compression spring 225 partially extends into a second cavity 227 within the elongated beam. The cover 221 also provides a second stopper 228 that engages with a projection 226 of the clamp element 212 to restrict the clamp element 212 from moving beyond a second position.

[0064] Figures 4A and 4B show the elongated beam 209 of the clamping system 204 described above in more detail. In each example, repeating elements in Figures 4A and 4B are not given reference numbers. As can be seen from the figures, a plurality of pressure chambers 217 are aligned within the elongated beam 209 in the longitudinal direction L. The pressure chambers 217 are connected to each other, i.e., interconnected, via interconnections consisting of channels 229 extending between the side walls 230 of adjacent pressure chambers 217. Each pressure chamber 217 has an opening 231 at one end and is closed at the other end 232. The channels 229 are provided close to the other end 232. One pressure chamber 217 is connected to the outside of the elongated beam 209 via a channel 233. As is clear from Figures 4A and 4B, the pressure chambers 217 are integrally arranged within the elongated beam 209 and within the same material piece that constitutes the receiving space 210. The pressure chambers 217 are interconnected internally, as they are interconnected via channels 229 that do not reach the outside of the elongated beams 209.

[0065] Figure 5 shows a clamping system 304 that differs from the clamping system 204 described above in that its elongated beam 309 is composed of two separate components 309-1 and 309-2. The main body 309-1 of the elongated beam may be manufactured separately from the auxiliary body 309-2 and attached later. The pressure chamber 317 is formed within the auxiliary body 309-2.

[0066] Figure 6 shows a clamping system 404 that differs from the clamping system 204 described in relation to Figures 3A-4B, in that the pressure chamber 417 is formed within a cylinder 434 located in a cavity 435 integrally formed with an elongated beam 409. Of course, as described in relation to Figure 5, it is possible to provide a cavity 435 within the auxiliary body, thereby allowing the different features of Figures 5 and 6 to be combined.

[0067] Figures 7A–7C show a clamping system 504 that differs from the clamping system 204 described later in relation to Figures 3A–4B in terms of its features. Firstly, the elongated beams 509-1 and 509-2 consist of two separate components 509-1 and 509-2. The main body 509-1 of the elongated beam may be manufactured separately from the auxiliary body 509-2 and attached later. The pressure chamber 217 is formed by an air hose 536 having a deformable wall. The hose 536 extends through a cavity 535 in the longitudinal direction L of the elongated beams 509-1 and 509-2. The hose 536 expands when a fluid is pressurized in the pressure chamber 517 and contracts when the pressure is released. When the hose 536 expands (see Figure 7B), it pushes the actuator 511 to its actuated position. The first compression spring 519 helps to push the fluid out of the pressure chamber 517 when the pressure drops by pushing the actuating member 511 upward (see Figure 7C). Additionally, a projection 526 of the clamping element 512 is positioned on the upper side of the clamping element 512 to engage with the second compression spring 525. This releases the end face 537 of the clamping element 512 for engaging with the second stop 528. Furthermore, the clamping element 512 is provided with a recess 538 for accommodating the first compression spring 519 when the clamping element 512 is in the second position, i.e., when it has moved to the right in the figure. No first stop or movement limiter is provided for the actuating member, as in the embodiments of Figures 3A-4B. Finally, a projection 599 is provided inside the receiving space 510 to form a hook. The projection 599 is used to suspend the tool 505. For insertion or removal, the tool 505 needs to be moved around the projection 599. Therefore, the receiving space 510 has a relatively large width D compared to the tool 505, which has a smaller width d. Consequently, the clamping element 512 has a relatively large stroke for clamping the tool 505.

[0068] Figure 8 shows a clamping system 604 that differs from the clamping system 504 in Figures 7A-7C in that the elongated beam 709 is made from a single piece of material. Thus, the cavity 635 is integrally formed within one piece of the elongated beam 609.

[0069] Figure 9 shows the bottom clamp system 706, which, apart from the different positions of the projection 725 of the clamp element 712, has the features of the clamp system 204 described in relation to Figures 2A-3B. The projection 726 cooperates with the second stopper 728, leaving the end face 737 free.

[0070] Clearly, the bottom clamping system 706 can be modified by applying any of the aforementioned features, such as a separate elongated beam within the cavity and / or a separate cylinder and / or a hose as a pressure chamber.

[0071] Figures 10A and 10B show the slender beam 709 in more detail. Its characteristics are similar to those described in relation to Figures 3A and 3B.

[0072] Figures 11A–11D illustrate how cavities 817 within an elongated beam 809 can be internally interconnected. First, an elongated beam 809 is provided (see Figure 11A), with cavities 817 inside. The cavities are not yet interconnected. Next (see Figure 11B), a milling tool is inserted through an opening 831 in one of the cavities 817. The milling tool has a slender stem 850 and a larger head 851. The milling tool is inserted in insertion direction I (see Figure 11C). The milling tool is moved toward another cavity 817 in machining direction M, thereby eroding the material of the elongated beam 809 and creating a channel 829 between the two cavities. As shown in Figure 11D, the cavities 817 are then interconnected.

[0073] Figure 12 shows another clamping system 904, different from the clamping system 304 described in relation to Figure 5, which differs in that the first compression spring 919 is located around the actuator 104 rather than within a cavity in the actuator 911. The first stop is not shown in Figure 12. The first compression springs of the other clamping systems shown in this application may also be located around their respective actuators.

[0074] Although the present invention has been described above with reference to numerous specific examples and embodiments, the present invention is not limited thereto. Instead, the present invention also encompasses the subject matter defined by the claims, which follows below.

Claims

1. A clamping system for a press brake, the clamping system comprising an elongated beam having a receiving space for receiving a portion of a bending tool, the elongated beam having at least two cavities formed therein, each of the at least two cavities having an opening to the outside of the elongated beam, A clamping system characterized in that at least two of the aforementioned cavities are interconnected internally.

2. The clamping system according to claim 1, further comprising a channel extending from at least one of the at least two cavities to the outside of the elongated beam.

3. The clamping system according to any one of claims 1 to 2, wherein the at least two cavities are interconnected via their respective side walls.

4. The clamping system according to any one of claims 1 to 3, wherein at least two cavities are interconnected at the end zones of the cavities facing the openings of each cavity.

5. The clamping system according to any one of claims 1 to 4, further comprising a cylinder in each of the at least two cavities.

6. The clamping system according to any one of claims 1 to 5, further comprising a piston in each of the at least two cavities or in the cylinder of each of the at least two cavities.

7. A press brake comprising the clamping system according to any one of claims 1 to 6.

8. A method for manufacturing an elongated beam for a press brake clamping system, wherein the elongated beam is provided with a receiving space for receiving a portion of a bending tool, and the method is a) A step of providing a long, slender beam, b) A step of forming at least two cavities within the elongated beam, wherein each of the two cavities has an opening to the outside of the elongated beam, c) Providing a fluid connection to each of the at least two cavities, Includes, The step of providing the fluid connection is characterized by interconnecting the at least two cavities by inserting a tool through its opening into at least one of the at least two cavities and machining toward the other of the at least two cavities.

9. The method according to claim 8, wherein step c) is performed by machining from one of the at least two cavities until one of the at least two cavities is interconnected with the other of the at least two cavities.

10. The method according to any one of claims 8 to 9, further comprising the step of forming a channel from at least one of the at least two cavities to the outside of the elongated beam.

11. The method according to any one of claims 8 to 10, further comprising the step of providing the interconnecting portions in the side walls of the at least two cavities.

12. The method according to any one of claims 8 to 11, further comprising the step of providing the interconnection portion in the end zone facing the opening of each cavity.

13. The method according to any one of claims 8 to 12, further comprising the step of inserting a cylinder into each of the at least two cavities.

14. The method according to any one of claims 8 to 13, further comprising the step of inserting a piston into each of the at least two cavities or into a cylinder inserted into the cavity.

15. The method according to any one of claims 8 to 14, comprising the step of inserting the tool in the insertion direction and moving the tool continuously in the machining direction, wherein the machining direction is at a non-zero angle with the insertion direction, preferably the machining direction is substantially perpendicular to the insertion direction.

16. The method according to claim 15, wherein the tool comprises a shaft and a head having a cross-sectional dimension larger than that of the shaft.

17. The method according to any one of claims 8 to 16, further comprising the step of performing step c) by milling.

18. The method according to any one of claims 8 to 17, further comprising the step of performing step b) by milling or drilling.

19. The method according to any one of claims 1 to 18, further comprising the step of forming the cavity in the part of the elongated beam that is integral with the part of the elongated beam having the receiving space, in step b).

Images