Patent Application
20230302515
The invention relates to a clamping system for a press brake, the clamping system comprising an elongate beam comprising a receiving space for receiving a part of a bending tool, the elongate beam having at least two cavities formed therein, wherein each of the at least two cavities has an opening to the exterior of the elongate beam.
Press brakes are machines used for bending or folding sheet material, such as metal sheets. For that purpose, press brakes include a bottom beam and a top beam, which are movable with respect to each other. The top and bottom beams both hold tools, between which a workpiece is provided for bending. In general, bending tools of a press brake are exchangeable to allow making different types of bends or folds, and to allow servicing the tools. Therefore, press brakes are provided with a clamping system which can releasably clamp the tools. Clamping systems may be provided on the top beam of the press brake, on the bottom beam, or on both.
Two types of press brakes can be distinguished. The first type has a clamping system that is an integral part of either the top or bottom beam. A further clamping system may or may not be provided for the other of the top or bottom beam. Such a clamping system, that is an integrated one, can not be detached from its top or bottom beam, and is itself thus not exchangeable with another clamping system, whereas the tools the clamping system can hold are exchangeable. The second type has an exchangeable clamping system that can be fixedly connected to either the top beam or the bottom beam. A further clamping system may or may not be provided for the other of the top or bottom beam. The exchangeable clamping system allows exchanging tools, but can also be detached from its top or bottom beam, for instance for maintenance or for exchanging it for another clamping system. This is in the art used to make one press brake suitable for different tooling types, which may require different clamping systems, and/or to service the clamping system.
Further clamping systems exist that can be clamped by other clamping systems as if they were a tool. Such clamping systems can for instance be clamped by a system for tools of a first type, whereas they themselves can clamp tools of a second type, so that such clamping systems act as an adaptor between a clamping system and a tool that would otherwise be incompatible.
The invention relates to clamping systems integrated with press brakes, be it the bottom beam or top beam, exchangeable clamping systems, and clamping systems acting as an adaptor, and to a method of making an elongate beam for any such clamping system.
A press brake and a clamping system therefor are known, for instance from applicant's earlier application WO 2010/056110 A1, which describes a clamping device for clamping a tool. The clamping device includes an actuated member and an engaging member. The actuated member is driven for instance hydraulically or pneumatically.
Although the clamping device described in WO 2010/056110 A1 has performed satisfactory, and to this day still does, a need exists to further improve the clamping device. This need exists in particular in increasing the reliability and in improving ease of manufacturing.
Therefore, the invention aims to provide a clamping system that is more reliable and can be manufactured relatively easily.
According to the invention, this aim is achieved by a clamping system for a press brake according to the preamble, characterized in that the at least two cavities are interconnected internally.
The cavities in the elongate beam may be used to house drive means, for instance for driving an actuating member of the clamping system, such as a piston. In particular, the cavities may each house a piston of an hydraulic or pneumatic actuation system, the piston preferably acting directly on a clamping element for engaging a tool in a receiving space of the elongate beam. The clamping element may be movable between a first position, in which it may engage on the bending tool for clamping it in the receiving space, and a second position for releasing the bending tool. Accordingly, the piston may constitute an actuating member.
It is envisioned the cavities extend parallel to each other at a distance from each other as seen in the length direction of the elongate beam. Accordingly, multiple drive means can be arranged along the length of the elongate beam to clamp multiple tools or to clamp a tool at multiple locations.
Since multiple drive means or parts thereof are provided in multiple cavities, a need exist to interconnect the cavities. By connecting the cavities internally, no external interconnection needs to be provided for the two connections. Accordingly, the added manufacturing effort to provide the external interconnection is no longer needed. Moreover, external connections, which can comprise e.g. conduits or wiring, are liable to failure due to them being exposed to external factors. Further, a point of connection between the elongate beam and the external interconnection may be prone to damage or failure, or require regular servicing. Accordingly, by providing the internal interconnection, the clamping system is less susceptible to failure and therefore more reliable. Accordingly, less service may be needed.
In particular, when the conduits carry hydraulic or pneumatic fluid, it takes a relatively long amount of time for the fluid to move through the conduits, and the conduits impose a relatively high resistance to flow on the fluid. Thus, by providing said internal connection, less time and/or pressure may be needed to move the hydraulic or pneumatic fluid, which in turn may aid in moving the clamping element faster. A tool can thereby be released and/or replaced faster.
Moreover, the cavities may be used directly as pressure chambers of a pneumatic or hydraulic drive system, for instance by inserting a piston in the cavities as will be explained below.
Additionally or alternatively, manufacturing the clamping system may be relatively easy, as no additional components need to be provided and installed for the external connection.
It is noted that internal herein refers to internal of the elongate beam. External herein refers to external of the elongate beam.
The at least two cavities may be formed integrally in the elongate beam, as opposed to being formed in a separate body fixed to the elongate beam.
This may present the advantage that no such separate body need be provided and later fixed and/or sealed to the elongate beamed. Accordingly, the clamping system is simplified, thereby removing possible points of failure and simplifying the manufacturing process. Moreover, the separate body would introduce an additional source of error in mutually positioning parts of the press brake, in particular in positioning the cavity with respect to the clamping element.
Additionally or alternatively, forming the at least two cavities integrally in the elongate beam may make it possible to produce the clamping system relatively cost efficiently.
The interconnection may be provided as a channel between the at least two cavities cut out of the material of the elongate beam.
In an embodiment of the clamping system, the clamping system further comprises a channel extending from at least one of the at least two cavities to an exterior of the elongate beam.
The channel may be used to supply the cavities or components therein with appropriate in- and/or output, for instance by running conduits and/or wiring through the channel. In particular, the channel could itself form a conduit through which a fluid could flow to the at least one of the at least two cavities. Such a fluid could be a hydraulic or pneumatic fluid.
The other of the at least two cavities could be provided with the same in- and/or output via its interconnection with the at least one of the at least two cavities.
In another embodiment of the clamping system, the at least two cavities are interconnected via their respective side walls.
Providing the interconnection in the side walls aids in preserving the structural rigidity of the elongate beam, since less material of the elongate beam needs to be removed to form the interconnection via the side walls, in particular since the cavities may be arranged next to each other, their respective side walls facing each other. Moreover, the interconnection may be provided in the side wall with relative ease as is explained below.
In yet another embodiment of the clamping system, the at least two cavities are interconnected at an end zone of the cavities that is opposite the opening of the respective cavity.
In this embodiment, the opening is left free, so that it can be used for instance for drive means in the cavities to engage on an actuating member of the clamping system. By placing the interconnection away from the opening, the drive means can be provided with in- and/or output through the interconnection, without interfering with operation of the drive means.
In yet another embodiment of the clamping system, the clamping system further comprises a cylinder in each of the at least two cavities.
The cylinder may be used as part of a pneumatic or hydraulic drive system for driving the clamping system, for instance for driving an actuating member of the clamping system.
The cylinder may be supplied with pneumatic or hydraulic fluid via the interconnection between the cavities, and/or via the channel. For this purpose, the pneumatic or hydraulic fluid may flow directly through the interconnection and/or the channel, or conduits may be provided which run through the interconnection and/or the channel.
In yet another embodiment of the clamping system, the clamping system further comprises a piston in each of the at least two cavities or in each cylinder in each of the at least two cavities.
The piston may be used as part of the pneumatic or hydraulic drive system for driving the clamping system, for instance for driving an actuating member of the clamping system. The piston may be movable in the cylinder inside the cavity and be configured to cooperate therewith, or the piston may be movable directly in the cavity and be configured to cooperate therewith. In the latter case, the cavity itself can serve as a cylinder for cooperation with the piston. In this case, no conduits are necessary, as pneumatic or hydraulic fluid can flow between the two cavities via the interconnection between them.
The 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-described features, alone or in any suitable combination.
The clamping system may be arranged in a top beam of the press brake, in a bottom beam of the press brake, or in both. The clamping system may be a separate, exchangeable clamping system, often referred to into the art as clamping beam, or may be an integral part of the press brake.
The invention also relates to a method of manufacturing an elongate beam for a clamping system for a press brake, the elongate beam comprising a receiving space for receiving a part of a bending tool, the method comprising the steps of:
characterized in that providing the fluid connection is performed by interconnecting the at least two cavities by inserting a tool into at least one of the at least two cavities through its opening, and machining towards another one of the at least two cavities.
According to the method, the interconnection between the at least two cavities is provided from the inside of a cavity towards another. As such, an interconnection can be provided that is internal to the elongate beam. As a result, the at least two cavities can be interconnected internally. This has the advantages described above in relation to the clamping system.
The method may be used to manufacture an elongate beam for use in a clamping system as described above, and may as such comprise the above-described features, alone or in any suitable combination.
In an embodiment of the method, step c) is performed by machining from the one of the at least two cavities until the one of the at least two cavities is interconnected with the other one of the at least two cavities.
In this embodiment, machining from one cavity to another takes place in a single direction. Accordingly, once means for machining have been set up in one cavity, machining can continue until the interconnection has been completed. This may aid in efficiently providing the interconnection. Moreover, there is no need to set up means for machining in the opposite direction from the other cavity, which reduces the total time needed for setting up the means for machining.
Further, as compared to an alternative wherein the interconnection is provided by machining from both cavities towards the other, it is not necessary to align the machine directions from each cavity, and to adjust the machining depths to each other.
In another embodiment of the method, the method further comprises forming a channel from at least one of the at least two cavities to an exterior of the elongate beam.
In yet another embodiment of the method, the method further comprises providing the interconnection in a side wall of the at least two cavities.
In yet another embodiment of the method, the method further comprises providing the interconnection in an end zone opposite the opening of each cavity.
In yet another embodiment of the method, the method further comprises inserting a cylinder into each of the at least two cavities.
In yet another embodiment of the method, the method further comprises inserting a piston into each of the at least two cavities or into the cylinders inserted therein;
In yet another embodiment of the method, the method comprises inserting the tool in an insertion direction and consecutively moving the tool in a machining direction, wherein the machining direction is at a non-zero angle with the insertion direction, preferably wherein the machining direction is substantially perpendicular to the insertion direction.
Accordingly, the interconnection can be provided e.g. in a side wall of the cavity and/or near an end zone removed from the opening of the cavity. The interconnection can extend laterally away from the cavity, so that cavities adjacent to each other, with respective side walls facing each other, as is the case with cavities arranged parallel to each other, can be interconnected.
In yet another embodiment of the method the tool comprises a shaft and a head, the head having a larger cross-sectional dimension than the shaft.
Using such a tool may avoid damage to the side wall of the cavity while machining.
In yet another embodiment of the method step c) is performed by milling A suitable milling tool may be used therefor.
The applicant has found that a suitable interconnection between cavities can be provided internally by milling.
In yet another embodiment of the method step b) is performed by milling or drilling.
The applicant has found that a suitable channel can be formed by milling or drilling. The channel may be formed from the outside of the elongate beam towards a cavity therein, for instance by drilling.
In yet another embodiment of the method, the method further comprises forming the cavities in step b) in a part of the elongate beam that is integral with the part of the elongate beam comprising the receiving space.
To the best of applicant's knowledge, press brakes so far have had cavities arranged in a separate body fixed to the elongate beam. This not only creates the need to provide a reliable fixing of the separate body to the elongate beam, but in many cases also requires suitable sealing of the separate body to the elongate beam. Even though adequate fixing and sealing techniques exist, both the fixing and the sealing remain points of possible failure, and must as such be serviced and/or inspected regularly to avoid failure of or damage to the clamping system. By forming the cavity integrally in the elongate beam, no separate body is needed. Accordingly, there is no fixing and/or a sealing of such a body which could constitute failures. Therefore, the clamping system is able to operate more reliably, and/or requires less servicing and/or inspection.
The invention will be further elucidated with reference to the attached drawings, in which:
In the figures, like elements are referred to with like reference numerals. Corresponding elements of different embodiments are referred to with reference numerals increased by a multiple of one hundred (100).
The actuating member 211 is movably arranged in a pressure chamber 217. The pressure chamber 217 is made directly into the elongate beam 209, which also has the receiving space 210. The pressure chamber 217 is thus integrally formed in the elongate beam 209. The actuating member 211 is provided with sealing means 218 which seal the actuating member 211 to the wall of the pressure chamber 217, i.e. to the inside of the elongate beam 209. As such, the actuating member 211 works as a piston moveable in the pressure chamber 217, which accordingly works as a cylinder. Accordingly, the actuating member 211 can be pushed towards its active position by introducing a fluid in the pressure chamber 217. The pressure chamber 217 of this clamping system 204 is adapted for receiving a hydraulic liquid as pressure fluid, in order to move the actuating member 211.
The clamping system 204 is provided with 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 arranged vertically, which corresponds to the pressing direction P defined by the clamping system 204, and the depth direction of the receiving space 210. The first compression spring 219 biases the actuating member 211 upwards, i.e. towards its inactive position. Accordingly, when pressure of the hydraulic liquid in the pressure chamber 217 is stopped, the first compression spring 219 pushes the actuating member 211 upwards further into the pressure chamber 217 thereby forcing the hydraulic fluid to flow out of the pressure chamber 217. The first compression spring 219 supports on a support 220 provided by a cover 221. The cover 221 covers clamping element 212, the actuating element 211 and the pressure chamber 217. The cover 221 also forms a first stop 222 for the actuating member 211 to hit, in order to limit movement of the actuating member 211 beyond the active position. The actuating member 211 has a movement limiter 223 for engaging the first stop 222. The first compression spring 219 extends partly in a first cavity 224 in 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 arranged horizontally, i.e. perpendicular to the pressing direction P and a longitudinal direction of the elongate beam 204. The second compression spring 225 acts on the clamping element 212 via a protrusion 226 thereof. the first compression spring 225 extends partly in a second cavity 227 in the elongate beam. The cover 221 also provides a second stop 228 for engaging the protrusion 226 of the clamping element 212, to limit the movement of the clamping element 212 beyond its second position.
Obviously, the bottom clamping system 706 could be altered by applying any of the features described above, such as the separate elongate beam and/or the separate cylinder in the cavity and/or the hose as a pressure chamber.
Although the invention has been described hereabove with reference to a number of specific examples and embodiments, the invention is not limited thereto. Instead, the invention also covers the subject matter defined by the claims, which now follow.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2026131 | Jul 2020 | NL | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/NL2021/050450 | 7/16/2021 | WO |
