Clamping system for a press brake having an integrally formed cavity or chamber, and press brake including such a clamping system

Abstract

The present invention relates to a clamping system for a press brake, the clamping system comprising: The clamping system comprises an elongate beam including a receiving space for receiving a portion of a bending tool, and a clamping element movable between a first position (wherein the clamping element can engage the bending tool to clamp it in the receiving space) and a second position for releasing the bending tool. The clamping system further comprises a pressure chamber that can be filled with fluid and an actuating member for driving the engaging element in response to the pressure of the fluid in the pressure chamber. The pressure chamber or a cavity housing the pressure chamber is integrally formed in the elongate beam. The present invention also relates to a press brake comprising such a clamping system.

Description

[Technical Field]

[0001] The present invention relates to a clamping system for a press brake, comprising an elongated beam including a receiving space for receiving a portion of a bending tool, a clamping element, a pressure chamber that can be filled with a fluid, and an actuating member for driving an engaging element in response to the pressure of the fluid in the pressure chamber, the clamping element being movable between a first position (a position in which it can engage the bending tool to clamp it in the receiving space) and a second position for releasing the bending tool.

[0002] A press brake is a machine used to bend or fold sheet material, such as sheet metal. To this end, a press brake includes a bottom beam and a top beam that are movable relative to one another. Both the top and bottom beams hold tools, between which a workpiece is presented for bending. Typically, the bending tools of a press brake are interchangeable to produce different types of bends or folds and to allow for tool maintenance. Therefore, press brakes are equipped with 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 brakes.

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

[0004] Further clamping systems exist that can be clamped by other clamping systems as if they were tools, for example, by a system for a first type of tool, but can itself clamp a second type of tool, so that such a clamping system acts as an adapter between clamping systems and tools that would otherwise be incompatible.

[0005] The present invention relates to clamping systems integrated with bottom or top beam press brakes, interchangeable clamping systems, and clamping systems that act as adapters.

[0006] A press brake and its clamping system 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 comprises an actuating member and an engaging member. The actuating member is, for example, hydraulically or pneumatically driven.

[0007] Although the clamping device disclosed in WO 2010 / 056110 A1 worked well and still works today, there is a need to further improve the clamping device, in particular to provide a clamping system that requires less inspection and / or testing or is more reliable. Summary of the Invention

[0008] It is therefore an object of the present invention to provide a clamping system that requires less inspection and / or testing or is more reliable.

[0009] According to the invention, this object is achieved by a clamping system for a press brake according to the preamble, characterized in that the pressure chamber or a cavity accommodating the pressure chamber is integrally formed in the elongate beam.

[0010] To the applicant's knowledge, press brakes have previously had a cavity for the cylinder located within a separate body secured to the elongated beam. This not only creates the need to securely secure the separate body to the elongated beam, but also often requires that the separate body be properly sealed to the elongated beam. Even when proper securing and sealing techniques exist, both the securing and sealing remain potential failure points and must therefore be periodically inspected and / or tested to avoid failure or damage to the clamping system. By integrally forming the pressure chamber or the cavity housing the pressure chamber within the elongated beam, a separate body is not required. Therefore, there is no securing and / or sealing of such a body that could constitute a failure. Therefore, the clamping system can operate more reliably and / or require less inspection and / or testing.

[0011] Furthermore, integrally forming the pressure chamber or cavity within the elongated beam, as opposed to a separate body fixed to the elongated beam, helps avoid tolerance issues. Indeed, introducing a separate body introduces an additional interface with its own tolerances. Therefore, deviations from the ideal position of the pressure chamber or cavity are added to the additional tolerances introduced at the separate body interface, thereby potentially increasing errors in positioning the pressure chamber or cavity. Therefore, by avoiding a separate interface, the pressure chamber or cavity can be more accurately positioned.

[0012] Additionally or alternatively, integrally forming a pressure chamber or cavity within the elongate beam allows the clamping system to be produced relatively cost effectively.

[0013] It should be noted that the fluid may be a liquid or a gas.

[0014] The pressure chamber may include an inlet and / or an outlet, or a combination of an inlet and an outlet, for introducing fluid into the pressure chamber and expelling fluid to the outside, respectively. The pressure chamber may be sealed away from any inlet and / or outlet. Thus, the pressure chamber may be configured to hold a fluid under pressure.

[0015] Integrally formed may be understood herein as being part of the same single piece, and therefore does not require a separate piece or component to be attached to the elongate beam to provide the pressure chamber or cavity that houses the pressure chamber.

[0016] In particular, the pressure chamber or cavity may be integrally formed entirely within the elongate beam, and therefore does not require an additional piece secured to the elongate beam to form and / or seal the pressure chamber.

[0017] In one embodiment of the clamping system, the actuation member is movable within said pressure chamber or cavity.

[0018] In this embodiment, the actuating member can move within the pressure chamber or cavity, so that it takes up less space outside the pressure chamber or cavity, thus allowing for a particularly compact design.

[0019] Providing a compact structure helps reduce the risk of the workpiece colliding with the press brake. For example, if the workpiece is to be bent multiple times, e.g., at different locations, the workpiece may be folded back toward the elongated beam. The elongated beam can then limit the size of the workpiece and / or the amount of bend that can be created in the workpiece before the elongated beam cuts off the workpiece during bending. Therefore, configuring the press brake compactly is important to allow space for as many workpieces as possible, so that the press brake can be used to bend complex shapes and / or relatively large workpieces with many folds. In another embodiment of the clamping system, the cavity or pressure chamber extends outside the elongated beam.

[0020] The actuating member may be movable within a pressure chamber or cavity such that the actuating member constitutes or comprises a pneumatic or hydraulic piston. Advantageously, this reduces the number of parts required. The actuating member may be movable between an actuated position that biases the clamping element toward the first position and an inactive position that moves the clamping element to the second position.

[0021] In the actuated position, the air or hydraulic pressure may be relatively high, while in the non-actuated position, the air or hydraulic pressure may be relatively low, so that pressure can be used to move the actuating member to its actuated position.

[0022] The actuating member may be movable in a direction parallel to a pressing direction defined by the clamping system, for example in a direction corresponding to the pressing direction of a press brake, which may correspond to the depth direction of the receiving space in the elongate beam.

[0023] In particular, the actuating member can act directly on the clamping element, so no further components are required to drive the clamping element, which benefits from helping to achieve an accurate construction and thereby avoiding the tolerance problems mentioned above.

[0024] It should be noted that the actuating member moving in the pressing direction is combined with an actuating member acting directly on the clamping element, allowing for a particularly compact construction while avoiding tolerance problems that would otherwise be caused by additional components required.

[0025] Direct interaction between the actuating member and the clamping member can be achieved, for example, when at least one of the clamping member and the actuating member has an engagement surface for engaging with the other of the clamping member and the actuating member, and at least a portion of the engagement surface is inclined relative to the direction of movement of the respective member.

[0026] Such inclined engagement surfaces provide transmission between the clamping element and the actuating member, so that the clamping element and the actuating member can be positioned at an angle relative to each other, thereby allowing for a relatively compact construction of the clamping system.

[0027] The angle at which the engagement surface is inclined can be selected to select an appropriate transmission ratio between the movement of the actuating member and the clamping element. This angle may vary smoothly or abruptly across the engagement surface to provide different transmission ratios at different positions on the engagement surface. In particular, the engagement surface may be curved or may consist of two sections with different inclination angles.

[0028] If the cavity or pressure chamber protrudes to the outside, a debouchment can be used to introduce a component into the cavity or pressure chamber, for example, a piston can be inserted into the pressure chamber or a cylinder can be inserted into the cavity.

[0029] In yet another embodiment of the clamping system, the clamping system further comprises a cover covering at least a portion of the cavity or pressure chamber.

[0030] Such a cover may protect the pressure chamber and / or cavity and may also protect the moving parts of the clamping system from, for example, dirt and / or may increase the safety of the clamping system by making the moving parts inaccessible to operators.

[0031] In yet another embodiment of the clamping system, the clamping system includes a plurality of interconnected pressure chambers or cavities.

[0032] Multiple pressure chambers or cavities can be used to drive multiple actuating members to move multiple clamping elements, thereby enabling clamping of tools of various lengths and / or clamping multiple tools simultaneously. In the case of pressure chambers, connecting them together can equalize the pressure in each chamber, or a single pressure chamber can be used to drive multiple chambers by pumping fluid in and out. In the case of cavities, interconnecting them can provide, for example, conduits and control lines for cylinders installed in the cavities.

[0033] The multiple pressure chambers or cavities may be aligned longitudinally of the elongate beam.

[0034] In yet another embodiment of the clamping system, the pressure chambers or cavities are internally interconnected.

[0035] By connecting the pressure chambers or cavities internally, additional potential points of failure are avoided and fewer seals are required compared to prior art where the cavities are interconnected through conduits external to the elongated beam. Such conduits require sealing to the elongated beam, which creates a potential point of failure. Additionally, external conduits are more susceptible to damage.

[0036] In particular, when the conduit carries hydraulic or pneumatic fluid, it takes a relatively long time for the fluid to move through the conduit, and the conduit imposes a relatively high resistance to flow over 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 faster, thereby allowing the tool to be released and / or replaced more quickly.

[0037] In yet another embodiment of the clamping system, the clamping system further includes a channel in the elongate beam connected to the pressure chamber or cavity for delivering fluid to and / or returning fluid to the pressure chamber or cavity.

[0038] By pumping fluid through the channels to and / or from the cavity or pressure chamber, the pressure chamber or cylinder housed within the cavity can be used as part of a pneumatic or hydraulic drive means for the actuating member.

[0039] In yet another embodiment of the clamping system in which the pressure chamber is integrally formed with the elongate beam, the actuation member includes a piston movable within the pressure chamber.

[0040] In this embodiment, the pressure chamber is integrally formed within the elongate beam, and the piston is movable within the pressure chamber. The piston is thus directly movable within the pressure chamber. The pressure chamber can therefore form, for example, a cylinder of a pneumatic or hydraulic drive means for driving the actuating member. As no separate cylinder is required, the amount of components required is reduced, thereby reducing the amount of potential points of failure.

[0041] In yet another embodiment of the clamping system, a cavity is integrally formed within the elongate beam, and the clamping system further comprises a cylinder housed within the cavity, the cylinder defining a pressure chamber, and the actuating member comprising a piston movable within the cylinder.

[0042] In this embodiment, the cavity is used to house a cylinder, which can be used, for example, as part of a pneumatic or hydraulic drive means for driving an actuating member. Using a cylinder separate from the elongated beam reduces tolerance constraints when determining the dimensions of the cavity, as only the cylinder and piston need to fit and seal together with relatively small tolerances. Therefore, the cavity within the elongated beam can be created relatively easily, quickly, and / or cost-effectively. Furthermore, providing a separate cylinder within the cavity reduces and / or eliminates sealing requirements for the cavity.

[0043] In yet another embodiment of the clamping system, the pressure chamber is defined by a deformable wall disposed within the cavity.

[0044] By forming the pressure chamber from a deformable wall, the pressure chamber can expand and contract upon supply and removal of fluid therefrom. In this way, the deformable wall can be used, for example, to move an actuating member, for example, by pushing it towards an actuated position when extended.

[0045] A flexible hose may be provided to form the deformable walls and may extend through the multiple cavities to provide interconnected pressure chambers with deformable walls within the multiple cavities.

[0046] In yet another embodiment of the clamping system, the pressure chamber is configured to receive hydraulic fluid.

[0047] The pressure chamber can therefore be used as part of a hydraulic drive means. The pressure chamber may form a hydraulic cylinder or a hydraulic chamber.

[0048] In yet another embodiment of the clamping system, the pressure chamber is configured to receive pneumatic fluid.

[0049] The pressure chamber can therefore be used as part of a pneumatic driving means, and can form a pneumatic cylinder or a pneumatic chamber.

[0050] In yet another embodiment of the clamping system, the actuating member is movable between an actuated position in which it biases the clamping element toward the first position and an inactive position in which it allows the clamping element to move to the second position, and the clamping system further comprises a first biasing member acting on the actuating member to bias the actuating member toward its inactive position.

[0051] Applicant discovered that a relatively large portion of the time required to change tools is consumed by displacing the clamping element toward its second position to release the tool. To move the clamping element toward its second position, for example, if the actuating member is pneumatically or hydraulically driven, the pneumatic or hydraulic pressure on the actuating member must be stopped, allowing the pneumatic or hydraulic fluid to flow back and return the actuating member to its inoperative position. However, it may take 10 seconds or more for the pneumatic or hydraulic fluid to retract sufficiently to release the tool. To facilitate the retraction of the pneumatic or hydraulic fluid, a first biasing member acting on the actuating member is provided. The biasing member biases the actuating member toward its inoperative position, thereby forcing the pneumatic or hydraulic fluid out when the pneumatic or hydraulic pressure is sufficiently released. As a result, the time required to return the actuating member to its inoperative position, thereby allowing the tool to be released, can be reduced to, for example, about 1-2 seconds.

[0052] Of course, the first biasing member may be used to perform a similar function when drive means other than pneumatic or hydraulic drive means are used.

[0053] For example, it should be noted that a first biasing member acting on the actuating member, rather than the clamping element, can provide a relatively large space for the first biasing member. In particular, the first biasing member acting on the actuating member can be relatively long and / or relatively wide. Thus, the first biasing member can be relatively large, allowing for a relatively high spring constant in the case of a compression spring, for example, so that the compression spring can provide a relatively large biasing force, which helps to reduce the time required to move the actuating member. The length of the spring can also, or alternatively, allow for a relatively wide range of movement of the actuating member while being biased by the spring.

[0054] The relatively wide range of motion of the actuating member is particularly important when a relatively large stroke of the clamping element is required. Some clamping systems include protrusions that act as hangers or hooks inside a receiving space, on which a tool can be supported and / or suspended. The receiving space is relatively wide compared to the tool, since the tool requires sufficient space inside the receiving space to manipulate the tool around the protrusion in order to insert or remove it. Such clamping systems require a relatively large stroke of the clamping element, since the clamping element must at least partially traverse the relatively wide receiving space.

[0055] It should be noted that the force exerted by the first biasing member must be overcome to move the actuating member into its actuated position. Thus, the overall force required to clamp the tool is increased by the first biasing member. This can be achieved by selecting an appropriately powerful drive means, such as a hydraulic or pneumatic drive means, to drive the actuating member.

[0056] A first biasing member acting on an actuating member can be understood here as the first biasing member acting initially on the actuating member. Of course, the actuating member can then act, for example, on a clamping element or, for example, on a drive means. It should be understood that, while the clamping element acts on the actuating member, for example, a biasing means acting initially on a clamping element is not understood here as acting on the actuating member. Thus, the first biasing member may act directly on the actuating member.

[0057] The first biasing means may act on any element that moves in the same direction and at the same speed as the actuating member, for example any element that is fixedly connected to the actuating member.

[0058] The invention also relates to a press brake comprising at least one clamping system as described above, which may have any of the above-described features, alone or in any suitable combination.

[0059] The clamping system can be located in the top beam of the press brake, in the bottom beam of the press brake, or both. The clamping system can be a separate, replaceable clamping system, often referred to in the art as a clamping beam, or it can be an integral part of the press brake. [Brief explanation of the drawings]

[0060] The invention will now be further described with reference to the accompanying drawings. [Figure 1A] FIG. 1A shows a schematic cross-sectional side view of a press brake with an interchangeable clamping system. [Figure 1B] FIG. 1B shows a schematic front view of a press brake with an interchangeable clamping system. [Figure 2A] FIG. 2A shows a schematic cross-sectional side view of a press brake with an integrated clamping system. [Figure 2B] FIG. 2B shows a schematic front view of a press brake with an integrated clamping system. [Figure 3A] FIG. 3A shows a schematic perspective cross-sectional view of the clamping system and tool. [Figure 3B] FIG. 3B shows a schematic cross-sectional view of the clamping system and tool. [Figure 3C] FIG. 3C shows a schematic cross-sectional view of the clamping system and tool. [Figure 4A] FIG. 4A shows a schematic perspective view of an elongated beam of the clamping system of FIGS. 3A-3C. [Figure 4B] FIG. 4B shows a schematic perspective view of an elongated beam of the clamping system of FIGS. 3A-3C. [Figure 5] FIG. 5 shows a schematic diagram of a variation of the clamping system of FIGS. 3A-5. [Figure 6] FIG. 6 shows a schematic diagram of a variation of the clamping system of FIGS. 3A-5. [Figure 7A] FIG. 7A shows a schematic perspective view of another clamping system and tool. [Figure 7B] FIG. 7B shows a schematic side view of another clamping system and tool. [Figure 7C] FIG. 7C shows a schematic side view of another clamping system and tool. [Figure 8] FIG. 8 shows a schematic diagram of a variation of the clamping system of FIGS. 7A-7C. [Figure 9] FIG. 9 shows a schematic cross-sectional view of yet another clamping system. [Figure 10A] FIG. 10A shows a schematic perspective view of an elongated beam of the clamping system of FIG. [Figure 10B] FIG. 10B shows a schematic longitudinal section of an elongated beam of the clamping system of FIG. [Figure 11A] FIG. 11A shows general steps in a method for interconnecting cavities in an elongated beam. [Figure 11B] FIG. 11B shows schematic steps in a method for interconnecting cavities in an elongated beam. [Figure 11C]FIG. 11C shows schematic steps in a method for interconnecting cavities in an elongated beam. [Figure 11D] FIG. 11D shows schematic steps in a method for interconnecting cavities in an elongated beam. [Figure 12] FIG. 12 shows a schematic diagram of a modification of the clamping system of FIG. Detailed Description

[0061] 3B, 3C, 5, 6, 7B, 7C, 8, 9 and 12 show views from the same side as FIGS. 1A and 2A.

[0062] In the figures, like elements are numbered likewise, and corresponding elements in different embodiments are referenced by reference numbers incremented by multiples of one hundred (100).

[0063] 1A and 1B show press brake 1 installed on ground surface G. Press brake 1 includes top beam 2 and bottom beam 3. Top beam 2 is provided with top clamping system 4, which removably holds top tool 5. Bottom beam 3 is provided with bottom clamping system 6, which removably holds bottom tool 7. Top beam 2 and bottom beam 3 are movable toward and away from each other via hydraulic system 8. Accordingly, 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, which are then moved toward each other. Top tool 5 then pushes the sheet metal into bottom tool 7 to bend and deform the sheet metal. After bending, tools 5 and 7 are moved away from each other by moving top beam 2 via hydraulic system 8. The clamping systems 4, 6 are removably attached to the top beam 2 and bottom beam 3, respectively, via a suitable locking system, so that the clamping systems 4, 6 can be replaced with clamping systems suitable for other tools, or the clamping systems 4, 6 can be removed for inspection.

[0064] 2A and 2B show a similar press brake 101, and only the differences from the press brake 1 of FIGS. 1A and 1B will be described here. The clamping systems 104, 106 of the press brake of FIGS. 2A and 2B are integrated with the top beam 102 and bottom beam 103, respectively. Therefore, the clamping systems 104, 106 are not interchangeable. The tools 105, 107 held by the clamping systems 104, 106 are interchangeable.

[0065] 3A-3C show a clamping system 204 that can be used, for example, in the press brake shown in FIGS. 1A-2B. The clamping system 204 has an elongated beam 209 as a main body. A receiving space 210 within the elongated beam 209 accommodates a portion of the tool 205. The clamping system further includes an actuating member 211 and a clamping element 212. The actuating member 211 is movable upward to an inoperative position and downward to an operative position. The clamping element 212 is movable between a first position in which it extends into the receiving space 210 to engage the tool 205 and a second position in which it retracts from the receiving space 210 to release the tool. The clamping element 212 has an engagement tip 213 that cooperates with an engagement recess 214 within the tool 205 to securely clamp the tool 205 within the receiving space 210. In the actuating position, the actuating member 211 engages with the clamping element 212 and urges it toward the receiving space 210. FIG. 3B shows the actuating member 211 in the actuating position such that the tool 205 is clamped within the receiving space 210 by the clamping element 212. The actuating member 211 has an inclined engagement surface 215 for engaging the clamping element 212, which in turn engages with an inclined engagement surface 216 of the cooperating clamping element 212. Thus, when the actuating member 211 moves to its actuating position, i.e., downward in the figure, the engagement surface 215 of the actuating member 211 engages with the engagement surface 216 of the clamping element 212, and due to its inclination, presses the clamping element 212 toward its first position (i.e., to the left in the figure). FIG. 3C shows the actuating member 211 in the inactive position, with the clamping element 212 retracted from the receiving space 210 to a second position, thereby releasing the tool 205.

[0066] The actuating member 211 is movably disposed within a pressure chamber 217. The pressure chamber 217 is formed directly within the elongated beam 209 and 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 seals the actuating member 211 to 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 piston that is movable within the pressure chamber 217, and the piston therefore functions as a cylinder. The actuating member 211 can therefore be pushed towards its actuated position by introducing a fluid into the pressure chamber 217. The pressure chamber 217 of this clamping system 204 is configured to receive hydraulic liquid as a pressure fluid for moving the actuating member 211.

[0067] The clamping system 204 comprises a first biasing member in the form of a first compression spring 219. The first compression spring 219 acts on the actuating member 211. The first compression spring 219 is arranged vertically, corresponding 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., towards its inactive position. Thus, when the pressure of the hydraulic 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 hydraulic fluid out of the pressure chamber 217. The first compression spring 219 rests 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 stop 222 against which the actuating member 211 abuts to limit movement of the actuating member 211 beyond the actuated position. The actuating member 211 has a travel limiter 223 for engaging the first stop 222. The first compression spring 219 extends partially into a first cavity 224 within the actuating member 211. A second biasing member is provided in the form of a second compression spring 225. The second compression spring 225 is disposed horizontally, i.e., perpendicular to the pushing direction P and the longitudinal direction of the elongated beam 204. The second compression spring 225 acts on the clamping element 104 via a protrusion 226 on the clamping element 212, and the first compression spring 225 extends partially into a second cavity 227 within the elongated beam. The cover 221 also provides a second stop 228 that engages the protrusion 226 of the clamping element 212 to limit movement of the clamping element 212 beyond the second position.

[0068] 4A and 4B show the elongated beam 209 of the clamping system 204 described in more detail above. In each example, repeated elements in FIGS. 4A and 4B are not given reference numerals. As can be seen, 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 interconnecting portions formed by channels 229 extending between side walls 230 of adjacent pressure chambers 217. The pressure chambers 217 have an opening 231 at one end and are closed at the other end 232. The channel 229 is located adjacent to the other end 232. One pressure chamber 217 is connected to the exterior of the elongated beam 209 via a channel 233. As can be seen from FIGS. 4A and 4B, the pressure chambers 217 are integrally arranged within the elongated beam 209 and are arranged within the same piece of material that forms the receiving space 210.

[0069] The pressure chambers 217 are interconnected via channels 229 that do not reach the outside of the elongated beam 209 and are therefore internally interconnected.

[0070] 5 shows a clamping system 304 that differs from the clamping system 204 described above only in that its elongated beam 309 is composed of two separate components 309-1 and 309-2. The elongated beam's main body 309-1 may be manufactured separately from and subsequently attached to the secondary body 309-2. A pressure chamber 317 is formed within the secondary body 309-2.

[0071] Figure 6 shows a clamping system 404 which differs from the clamping system 204 described in relation to Figures 3A-4B only in that the pressure chamber 417 is formed in a cylinder 434 which is located in a cavity 435 which is integrally formed with the elongated beam 409. Of course, it is possible to provide the cavity 435 in the auxiliary body, as described in relation to Figure 5, thereby making it possible to combine the different features of Figures 5 and 6.

[0072] 7A-7C illustrate a clamping system 504 that differs from the clamping system 204 described in connection with FIGS. 3A-4B only in the following features. First, the elongated beams 509-1, 509-2 consist of two separate components 509-1 and 509-2. The elongated beam's main body 509-1 may be manufactured separately from the secondary 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, 509-2. The hose 536 expands when fluid is pressurized in the pressure chamber 517 and contracts when the pressure is released. When the hose 536 expands (see FIG. 7B), it pushes the actuating member 511 to its actuated position. The first compression spring 519 pushes the actuating member 511 upward, thereby helping to expel fluid from the pressure chamber 517 when the pressure is reduced (see FIG. 7C). A protrusion 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 frees the end face 537 of the clamping element 512 for engagement with the second stop 528. The clamping element 512 also has a recess 538 for accommodating the first compression spring 519 when the clamping element 512 is in the second position, i.e., when moved to the right in the figure. As in the embodiment of FIGS. 3A-4B, no first stop or travel limiter for the actuating member is provided. Finally, a protrusion 599 is provided inside the receiving space 510, forming a hook. The protrusion 599 is used to hang the tool 505. For insertion or removal, the tool 505 must be moved around the protrusion 599. Thus, the receiving space 510 has a relatively large width D compared to the tool 505, which has a smaller width d. The clamping element 512 therefore has a relatively large stroke for clamping the tool 505.

[0073] Figure 8 shows a clamping system 604 that differs from clamping system 504 of Figures 7A-7C in that elongated beam 709 is made from a single piece of material. Thus, cavity 635 is integrally formed within the single piece of elongated beam 609.

[0074] 9 shows a bottom clamping system 706 that has the features of the clamping system 204 described in connection with FIGS. 2A-3B, apart from the different position of the projection 725 of the clamping element 712. The projection 726 cooperates with a second stop 728, leaving an end face 737 free.

[0075] Obviously, the bottom clamping system 706 can be modified by applying any of the above mentioned features such as a separate elongated beam within the cavity and / or a separate cylinder and / or hose as a pressure chamber.

[0076] Figures 10A and 10B show elongated beam 709 in more detail, the features of which are similar to those described in connection with Figures 3A and 3B.

[0077] 11A-11D illustrate how cavities 817 within elongated beams 809 can be internally interconnected. First, elongated beams 809 are provided (see FIG. 11A) with cavities 817 therein. The cavities are not yet interconnected. Next (see FIG. 11B), a milling tool is inserted through opening 831 of one cavity 817. The milling tool has a thin stem 850 and a larger head 851. The milling tool is inserted in insertion direction I (see FIG. 11C). The milling tool is moved toward another cavity 817 in machining direction M, thereby eroding the material of elongated beam 809 and creating a channel 829 between the two cavities. As shown in FIG. 11D, the cavities 817 are then interconnected.

[0078] Figure 12 shows another clamping system 904 that differs from the clamping system 304 described in connection with Figure 5 in that the first compression spring 919 is provided around the actuating member 104 rather than within a cavity in the actuating member 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 provided around their respective actuating members.

[0079] While the present invention has been described above with reference to numerous specific examples and embodiments, the invention is not limited thereto. Instead, the present invention also encompasses subject matter defined by the claims, which follow.

Claims

1. In clamping systems for press brakes, an elongated beam including a receiving space for receiving a portion of a bending tool; a clamping element movable between a first position in which it can engage the bending tool to clamp it into the receiving space and a second position in which it can release the bending tool; a pressure chamber that can be filled with a fluid; an actuation member that drives the clamping element in response to the pressure of the fluid in the pressure chamber; Equipped with the pressure chamber or the cavity accommodating the pressure chamber is integrally formed in the elongated beam; A clamping system, characterized in that the actuating member is movable within the pressure chamber or the cavity in a direction parallel to the depth direction of the receiving space.

2. The clamping system of claim 1 comprising a plurality of interconnected pressure chambers or cavities.

3. The clamping system according to any one of claims 1 to 2, wherein the pressure chambers or cavities are interconnected within the elongate beam.

4. 4. The clamping system of claim 1, further comprising a channel in the elongate beam connected to the pressure chamber or cavity for feeding and / or returning fluid to the pressure chamber or cavity.

5. A clamping system according to any preceding claim, wherein the pressure chamber is integrally formed with the elongate beam, and the actuating member comprises a piston movable within the pressure chamber.

6. 5. The clamping system of claim 1, further comprising a cavity integrally formed within the elongate beam, the clamping system further comprising a cylinder housed within the cavity and defining the pressure chamber, the actuating member comprising a piston movable within the cylinder.

7. The clamping system according to any one of claims 1 to 4, wherein the pressure chamber is defined by a deformable wall disposed within the cavity.

8. The clamping system of any one of claims 1 to 7, wherein the pressure chamber is configured to receive hydraulic fluid.

9. The clamping system according to any one of claims 1 to 7, wherein the pressure chamber is configured to receive a pneumatic fluid.

10. 10. The clamping system of claim 1, wherein the actuating member is movable between an actuated position that biases the clamping element towards a first position and an inactive position that moves the clamping element to a second position, the clamping system further comprising a first biasing member acting on the actuating member to bias the actuating member towards its inactive position.

11. 11. The clamping system according to claim 1, wherein at least one of the clamping element and the actuating member comprises an engagement surface for engaging with the other of the clamping element and the actuating member, at least a portion of the engagement surface being inclined relative to the direction of movement of each element.

12. A press brake comprising at least one clamping system according to any one of claims 1 to 11.

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