The present disclosure generally relates to plate roll bending machines and, more particularly, to plate roll bending machines having hydraulic cylinders.
The present disclosure relates to roll bending machines having three or four rolls, which are well known in the metal fabricating industry for rolling metal plate into cylinders, obrounds and cone shapes. This type of machine uses hydraulic cylinders to change the relative position between the various rolls of the machine, and also hydraulic motors to rotate the rolls, such that plates can be formed in any desired shape.
The hydraulic systems of such machines commonly utilize a centrally located hydraulic manifold on which proportional valves, counterbalance valves, solenoid valves, flow control valves, oil pressure sensors and the like are mounted to operate hydraulic cylinders or motors that power and position gripping and bending rolls. In certain machines, the hydraulic manifolds are manufactured to National Fluid Power Association (NFPA) standard dimensions or International Standard Organization (ISO) standard dimensions and can be purchased from catalogs of various manufacturers. Similarly, the cylinders are manufactured to NFPA or ISO standard dimensions and can be purchased from catalogs form various manufacturers.
In a typical roll bending machine, pressurized hydraulic fluid is provided from a hydraulic pump into a manifold, which contains valves and other flow control devices that are fluidly connected, via tubes and hoses, to the various actuators of the machine. The various actuators are selectively activated to advance the plate and position the rolls such that a plate is bent to a desired radius. However, various variables may affect the final shape of the plate, which is typically addressed by experienced operators adjusting the various settings of the machine until a desired plate shape is produced. The variability in the plate shape can result from any number of factors such as the thickness and hardness of the plate, flexing in the bending or gripping rolls of the machine, and others.
In the past, plate roll bending machine manufacturers have attempted to improve the roll process in terms of accuracy in the shape of the bent plate while also minimizing undesirable effects in different ways. One such example can be seen in U.S. Pat. No. 5,890,386 to Davi, which issued on Apr. 6, 1999. Davi describes a roll bending machine in which typical undesirable effects in the bent plate, which are commonly referred to as trumpeting or barreling, are sought to be controlled. These effects, which produce cylinders having their seam either diverging or converging, as shown in
The present disclosure relates to a plate roll bending machine that automatically performs a pre-bending operation, in which various physical properties of the material of the plate can be determined, and then performs one or more finishing bending operations, which take into account the physical properties of the material that were determined during the pre-bending operation, to provide a finished roll at a desired dimension.
In one aspect, the disclosure describes a hydraulic roll bending machine having a top roller, a bottom roller and at least one bending roller. The hydraulic roll bending machine further includes an electronic controller, which includes a material database stored in non-volatile memory, the material database including a material information library of material properties for a plurality of materials. An actuator is associated with the at least one bending roller and operates in response to a bending signal provided by the electronic controller. A motor is coupled with one of the top or bottom roller and operates in response to a feed signal provided by the electronic controller. A position sensor is disposed to measure a position of the at least one bending roller relative to the machine and configured to provide a position signal to the electronic controller.
In one embodiment, the electronic controller is programmed and configured to load a plate between the top roller and the bottom roller; receive a user input indicative of a desired plate radius from a machine user; calculate a pre-bend radius for the plate based on the desired plate radius and information from the material database; provide a bending signal to the actuator to position the at least one bending roller relative to the top and bottom rollers based on the pre-bend radius; provide a feed signal to advance a leading portion of the plate against the at least one bending roller; determine an actual pre-bend radius of the leading portion of the plate; and calculate an adjustment to the material database based on a difference between the pre-bend radius and the actual pre-bend radius.
In another aspect, the disclosure describes a method for operating a hydraulic roll bending machine having a top roller, a bottom roller and at least one bending roller. The method includes using an electronic controller associated with the hydraulic roll bending machine, the electronic controller including a material database stored in non-volatile memory, the material database including a material information library of material properties for a plurality of materials. The method further includes providing an actuator associated with the at least one bending roller, the actuator operating in response to a bending signal provided by the electronic controller; providing a motor coupled with one of the top or bottom roller, the motor operating in response to a feed signal provided by the electronic controller; and providing a position sensor disposed to measure a position of the at least one bending roller relative to the machine, the position sensor configured to provide a position signal to the electronic controller.
In one embodiment, the method includes loading a plate between the top roller and the bottom roller; receiving a user input indicative of a desired plate radius from a machine user into the electronic controller; calculating a pre-bend radius for the plate based on the desired plate radius and information from the material database using the electronic controller; providing a bending signal to the actuator to position the at least one bending roller relative to the top and bottom rollers based on the pre-bend radius using the electronic controller; providing a feed signal to advance a leading portion of the plate against the at least one bending roller using the electronic controller; determining an actual pre-bend radius of the leading portion of the plate, and providing the actual pre-bend radius to the electronic controller; and calculating an adjustment to the material database based on a difference between the pre-bend radius and the actual pre-bend radius using the electronic controller.
In yet another aspect, the disclosure describes an electronic controller associated with a hydraulic roll bending machine, the hydraulic roll bending machine having a top roller, a bottom roller, at least one bending roller, an actuator associated with the at least one bending roller, a motor coupled with one of the top or bottom roller, and a position sensor disposed to measure a position of the at least one bending roller relative to the machine. The electronic controller includes a material database stored in non-volatile memory, the material database including a material information library of material properties for a plurality of materials; a connection to the actuator, which actuator configured to operate in response to a bending signal provided by the electronic controller; a connection to the motor, the motor configured to operate in response to a feed signal provided by the electronic controller; and a connection to the position sensor, the position sensor configured to provide a position signal to the electronic controller.
In one embodiment, the electronic controller is programmed and configured to load a plate between the top roller and the bottom roller; receive a user input indicative of a desired plate radius from a machine user; calculate a pre-bend radius for the plate based on the desired plate radius and information from the material database; provide a bending signal to the actuator to position the at least one bending roller relative to the top and bottom rollers based on the pre-bend radius; provide a feed signal to advance a leading portion of the plate against the at least one bending roller; determine an actual pre-bend radius of the leading portion of the plate; and calculate an adjustment to the material database based on a difference between the pre-bend radius and the actual pre-bend radius.
In one aspect, the disclosure relates to a hydraulic roll bending machine, which includes a frame and a plurality of hydraulic cylinders, the rotation and/or relative position of which can be controlled to achieve a desired shape in a plate to be bent. The machine includes a controller that is configured to calculate a required roll positioning scheme and roll activation sequence to produce a pre-bend or a bend operation on a plate. The controller includes information about the material to be processed, and also corrects for unknown factors affecting the material forming process, by performing a bending operation in two stages, a learning stage and a bending stage, each time an operation is carried out. More specifically, the controller operates to provide, in the first instance, a rough bend that approximates the final, desired dimension. The rough bend, which is performed in the learning stage, is carried out with a factor of safety or risk factor, which determines the extent of under-bending that the machine will calculate based on predefined parameters. This calculation may factor in the yield strength of the material variations in the thickness of the material, the finish of the material, as it may affect traction between the material and the rollers of the bending machine, the temperature of the material and other factors that may affect the behavior and spring-back of the material during and after bending.
After the initial or rough bend is carried out, feedback observed by the user and/or acquired by machine sensors relative to an actual bend radius of the machine versus the desired or commanded bend radius, is provided to the controller to indicate the resulting radius. The controller, based on the feedback information on the resulting radius of the bend, compares the actual dimension with a calculated dimension to determine a correction factor. The correction factor, which is indicative of the extent of variability of the particular plate being shaped to a nominal set of attributes for a plate of the type that is predefined in the controller, is applied to determine an appropriate bending configuration that will produce a plate shape of desired dimensions. The controller then applies the bending configuration, without the safety or risk factor, to cause the machine to produce a plate with a desired shape. The bending configuration may be understood as a correction factor of the material properties as observed during the initial bend, which correction factor is applied to the predefined properties of the material as they are stored in the machine controller. This two-step process in which the particular corrections that are required to counter any variability in the workpiece is repeated for every plate and for every bending operation.
In the description that follows, a four-roll bending machine is shown and described but it should be appreciated that the controller and methods described herein are applicable to machines having different roll number configurations and/or machines of various sizes. A partially disassembled view of a roll bending machine 100 in accordance with the disclosure is shown in
The machine 100 further includes front and rear bending rolls 116 (only one is visible in
A block diagram of the controller 119 that is part of the machine 100 is shown in
In the illustrated, exemplary embodiment, the controller 119 is associated with a user interface device 202, which can include any suitable haptic and/or electronic display that can be used to convey information to a user as well as be used by the user to provide information to the controller 119 via an input/output line 204. The controller 119 is also connected to other devices and configured to receive information from various sensors and other devices that is indicative of machine operating parameters. As shown, the controller 119 receives a position signal 206, which is indicative of the absolute or relative position of one or more of the various cylinders positioning the rolls in the machine, a speed signal 208, which is indicative of the rotational speed of the various rolls in the machine, a measurement signal 210, which is indicative of a measured dimension of a workpiece, and others. It should be appreciated that the various signals 204, 206, 208 and 210 are representative examples of various signals that pertain to the shaping operation carried out by the machine 100 and can be replaced by fewer or more such signals for a particular machine implementation.
The controller 119 further includes various internal modules or functions that carry out various processes. These include at least a user module 212, a material database 214, a machine geometry 216, a calculator 218 and a sequencer 220. Other modules may also be included. From a general aspect, the user module 212 includes information for authorized users of the device, and can allow the various users, which can access the controller using unique credentials, to control various levels of machine functionality and also set their desired machine environment in terms of language, units and others. The material database 214 includes predefined material information such as physical parameters, yield strength, harness and the like. The information in the material database may be populated based on known materials that will be used with the machine, which have predefined properties, and may also be populated by manually added materials by a user or other source of information. The machine geometry 216 includes precise information on the size and shape of the machine and its actuators to enable an exact application of force to deform work pieces in the machine.
The calculator 218 includes the mathematical relations used by the controller to calculate the initial force application and also the finishing force application described above onto the workpiece by the machine rollers and their position. The calculator may operate based on various physical equations or models. The sequencer 220 may include various structures that interface between the controller 119 and the various systems and actuators of the machine 100. During operation, the sequencer may provide the various commands and indications to the user that operate the machine in the contemplated fashion.
A flowchart for a method of operating a plate roll bending machine is shown in
In accordance with the method, at Step 1, the machine assumes a starting configuration, which facilitates loading and positioning of the plate relative to the machine and rollers. In this configuration, the bottom roller C, which, for example, corresponds to the bottom roller 110 in
At Step 2, hydraulic pressure is applied to raise the bottom roller C to clamp the plate between itself and the top roller D. The hydraulic pressure or force is calculated by machine controller so as not to locally deform the plate but to apply sufficient force to hold the plate between the top and bottom rollers securely and also determine the actual thickness of the plate, which may deviate from a nominal thickness by an acceptable degree but which may also incrementally increase the height of the plate material to be bent, which the machine will determine dynamically at a later Step.
At Step 3, the top and/or bottom rollers D and C are rotated to align a leading edge of the plate in the feeding direction, in a vertical direction, with the centerlines of the top and bottom rollers D and C. The distance by which the plate must travel in the reverse feeding direction is known based on the positions of the right bending roller B at Step 1 or 2. In the aligned position, the centerlines of the top and bottom rollers C and D are coplanar with the leading edge of the plate. At Step 4, the right bending roller B is lowered to be below the horizontal plane defined by the plate. The vertical position of the right bending roll B in this Step can be determined based on a preset machine parameter and also based on the position of the bottom roller C.
At Step 5, the rollers assume a pre-bending position, in which the left bending roller A is raised so as to create an arc in the plate as the plate is advanced in the feeding direction towards the right of the figures through the machine. The resulting radius of the arc imparted to the plate can be determined based on a percentage offset from a desired, final bend radius of the plate and also based on the physical characteristics of the material of the plate such as its modulus of elasticity, thickness, yield strength and others. In general, the position of the left bending roll A in this Step can also be based on a user input of a desired radius.
At Step 6, the rollers are rotated to advance the plate through the machine in the feeding direction such that a pre-bend is imparted on the plate. In this Step, the plate is advanced enough to reach the right bending roller B. When a sufficient length of the plate has been advanced, the left bending roller is lowered at Step 7 out of the way of the plate, for example, to a height that is vertically aligned with the bottom roller C, and the right bending roller B is raised at Step 8 to contact the plate and push it up, thus lowering the trailing portion of the plate to reestablish contact with the left bending roller A. In this position, the machine adjusts the heights of the rollers based on the parameters previously mentioned and also based on an expected spring-back of the plate material.
In one embodiment, the machine automatically calculates the resulting radius of the plate based on the position of the rollers C, D and B, when the right bending roller B contacts the plate. Alternatively, or additionally, the machine user may measure the resulting radius and input the measured value to the controller via the user interface. The machine controller will compare the commanded pre-bending radius with the automatically determined or measured resulting radius of the plate following the pre-bending operation and, based on the difference, determine any empirical adjustment that should be made to the material properties for the particular plate and for the particular bending operation. With the adjustments complete, the controller will store the revised material properties, or a correction to previously stored material properties, for use in subsequent steps of the bending operation.
At Step 9, the plate is advanced through the machine to achieve the desired radius until a hold point, which includes leaving a straight portion at the trailing edge portion of the plate. For performing Step 9, the machine controller uses the correction factor to the material properties, in conjunction with predefined material properties, for the particular plate, to calculate a roller position that will achieve a desired bend radius for the plate. At Step 10, the user supports the cylindrical portion of the plate to complete the bend past the hold point, which involves raising the right bending roller B even more at Step 11 so that the trailing portion of the plate is bent at a smaller radius and springs back to the desired radius. In Step 11 as well, the updated or corrected material properties are used for a calculation of the bending radius that is applied to the plate. At Step 12, the right bending roller B adjusts in position and the plate is rolled to its final shape. At Steps 13, 14 and 15, the rollers are moved to their unloading positions and the rolled plate is removed from the machine.
Each of
A user interface that controls the material calculation of the machine controller, which can be used to calculate the pre-bending radius as previously described, is shown in
Button 12 allows selection of a known material that is stored in the machine controller. Button 13 allows definition of a new material. Button 14 shows a graphical representation of the physical properties of a material, which is generated automatically by the machine controller. A sample chart is shown in
A user interface in which a user may input various dimensions 222 that are specific to the machine in which the machine controller operates is shown in
A dash board showing various machine parameters during operation is shown in
The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
Number | Name | Date | Kind |
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5187959 | Davi | Feb 1993 | A |
5890386 | Davi | Apr 1999 | A |
20130233039 | Boissin | Sep 2013 | A1 |
Number | Date | Country | |
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20180133772 A1 | May 2018 | US |
Number | Date | Country | |
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62420874 | Nov 2016 | US |