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1. WO2018130945 - IMPROVED BENDING PRESS

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[ EN ]

IMPROVED BENDING PRESS

The invention relates to an improved bending press and the relevant operation method. WO2016/063579 and EP1160024, taken here as an example of the technological field of interest, describe a bending press and related tool storage equipped with a tool displacement mechanism.

The electronic control of the press determines from time to time which tool to withdraw from the storage with a runner and where to place it on the pressing table. Clearly, the position of each tool relative to the supporting frame of the storage must be known in advance, and a positional database is used for this purpose. To set up the press, also the final positions of the tools on the pressing table must be pre-determined and programmed, and to this aim a second positional database is used.

Programming the second positional database is long and complex, because for each preparation of the press one must patiently associate to each tool its final position on the pressing table. This is done by inserting numerical coordinates into the database, e.g. how many millimeters with respect to a reference.

It is evident that this procedure is not only laborious and boring, but also prone to errors. The operator must know the structure of the press and tools very well to express the positional data in numbers. In short, it is a very expensive trial-and-error process as to man hours.

The main object of the invention is to propose a variant of press and operation method thereof to this state of the art.

Another object is to solve or mitigate the aforementioned problems related to programming the second database.

A method is therefore proposed for controlling the positioning of a tool on a pressing table comprised in a bending press, comprising the steps of:

detecting by an electronic device an action performed in real time by a human operator, processing an electrical signal, generated by the electronic device due to said action, to calculate a coordinate of the tool relative to the pressing table,

moving the tool at or toward such coordinate.

Another aspect of the invention refers to a method for positioning a tool on a pressing table comprised in a bending press, comprising the steps of:

generating an electrical signal indicative of an action performed in real time by a human operator;

processing the signal to calculate a coordinate of the tool relative to the pressing table; moving the tool at or toward such coordinate.

Thus, it is no longer necessary to enter numerical data (which are little significant and intuitive) to program the position of the tool on the table. The operator instead manages to program it in an analog way, thanks to direct association between one of his actions and the movement of the tool. Other advantages are e.g. that

programming becomes very fast, because the system got rid of entering numbers via keyboard or similar interfaces;

it is easy to make small adjustments to the position for a tool already on the table, because the reference for the new displacement becomes visually the actual position;

the problem of the considerable complexity of manually entering numerical positional data of the tools, is solved.

Another aspect of the invention relates to a bending press comprising means, e.g. an electronic circuit like in particular a microprocessor, for performing the steps of one or each method. In particular the bending press preferably comprises:

a pressing table,

a drive for moving a tool on - and/or relative to - the pressing table,

an electronic device for detecting an action performed in real time by a human operator, an electronic circuit for, or a microprocessor programmed for, performing the steps of:

- processing an electric signal generated by the electronic device due to said action in order to calculate a coordinate of the tool relative to the pressing table, and

- driving the drive to move the tool at or toward such coordinate.

Preferably the microprocessor of the press is programmed with software instructions to perform one or each of the steps defined here for one or each method.

Preferably said microprocessor is permanently installed onboard the press, but it could also be part of an electronic board connected to the press only during the programming of the second database.

Another aspect of the invention relates to a program for microprocessor which, when executed by the microprocessor, causes the microprocessor to perform the steps of one or each method; or the steps indicated for the microprocessor comprised in the press.

Preferably the methods are executed or implemented by means of instructions of said microprocessor; however, the reference to a "microprocessor" includes also a discrete-component logic electronic circuit without a microprocessor (e.g. a ROM or a logic network). Where a method envisages the visualization or generation of images or symbols,

preferably such step is performed through a display, in particular controlled by the microprocessor for displaying and/or graphically updating the image or symbol defined in the method.

Said detected action can be a gesture (e.g. a movement of the arm, hand or head) and/or a word (via speech recognition). So the human-press interaction is enormously simplified because the tool position is no longer established with numbers to be entered but with analog procedure. That is to say, that the methods create a correspondence between an action of the operator and the movement or position of the tool on the table, so for example the position of a hand, a finger or an arm becomes the model of the tool position (the position of the finger or arm relative to a spatial reference expresses and controls in an analog way the position of the tool).

A preferred variant of the methods, or another stand-alone method, has the (further) steps of:

converting the spatial position of a part of an operator's body (a hand, finger, etc.) into an electrical signal, and

moving the tool on the table as a function of the signal so that the tool moves in accordance with the movement of the body part.

How to perform said conversion of spatial position, or said detection by an electronic device, depends on the part of the body to be detected. In general the methods can exploit, and/or the press can comprise, as electronic device, e.g.

- a proximity sensor, and/or a camera, and/or an infrared or ultrasound sensor to determine the position e.g. of a hand or an arm; and/or

- a joystick and/or a rotary knob to translate into an electrical signal a gesture of a hand (and/or a direction command for the tool); and/or

- a touch screen, to detect the position and/or movement of a finger; and/or

- an image projector with the ability of detection of a hand, to detect the position and/or movement of a finger or hand on a projected image, e.g. on the table of the press; and/or

- a microphone or acoustic sensor to detect the voice of the operator from which to extract voice commands to move the tool.

The step of moving the tool relative to the table as a function of the signal may preferably take place in such a way as to let a displacement of the part of the body correspond to a proportional or symmetrical displacement in real time of the tool, in particular maintaining the same direction. So it becomes very intuitive to move the tool, without even the operator having to watch or pay attention to his/her own part that he/she is moving.

To facilitate the placement of the tool, preferably the method envisages to generate a spatial reference so that the operator can compare it with the displacement of said part, the spatial reference corresponding to one or more points of the tool's stroke on the table. Thus the operator can mentally guess and/or calculate how much to move his/her own part to move the tool into a desired position. E.g. it is advantageous that the method envisages to generate as spatial reference the end-of-travel limits and/or the total stroke of the tool relative to the table.

Even more advantageous is that the method also envisages to generate a symbol indicating the actual position of the tool on the table, or a slider. Preferably, the slider is displayed close to or superimposed on said spatial references to improve the correspondence between the image and the movable mechanical parts on the press.

Said generation step takes place preferably by visualization, e.g. by reproducing or projecting on a screen or display, one or each of said spatial references. The screen or display is preferably comprised in the electronic device or in the press. A particular preferred embodiment of the spatial references is illustrated and described with reference to the attached figures.

To ease the placement of the tool, preferably the method envisages to generate or display a second slider near the first one, so that the operator can move the second slider through the displacement of said part. The movement of the second slider is interpreted as a command for fine displacement of the tool, and corresponds to a tool movement on the table with a lower pitch or to a displacement relative to a neighborhood of its current position. In particular, the electronic circuit, or the microprocessor, has the function of

generating a second slider near the first one,

interpreting a displacement of the second slider as a displacement on reduced scale of the tool;

calculating a destination coordinate of the tool relative to the pressing table with such reduced scale. Like before, the drive will then be driven to move the tool in or towards that coordinate.

To ease the placement of the tool, preferably the method envisages to generate or display an image representing a neighborhood, or a magnification of the current tool position, and the first and/or second sliders are displaceable with respect to said image; preferably they are displaceable within said image. Thus the operator can easily guess and/or mentally calculate how much to move his/her own part to move the tool precisely in a desired position.

To ease the management of the tools to be placed, preferably the method envisages to generate or display an image that represents a menu or a list of tools from which to select the tool to be moved.

A preferred variant of the methods, or a stand-alone method, has the (further) steps of: detecting the position of a finger on a touch-screen (preferably associated to the press), calculating from the finger's position a coordinate for the tool related to the pressing table,

moving the tool to or towards that coordinate.

Preferably, the methods envisage that said symbol moves following the action performed by the operator, so as to immediately give feedback on the tool position.

A preferred variant of the methods has the further step of:

saving the coordinate calculated from the signal emitted by the electronic device.

Preferably, the saving takes place in a memory, e.g. connected to the microprocessor, of the bending press, and even more preferably a plurality of coordinates calculated as above are saved to form a database of tool positions to be consulted during a phase in which a set of tools are set up on the table of the press.

The following variants apply to all the aspects of the invention mentioned above:

- the displaceable tools can be those of the lower or upper table, and consist of punches, dies or the so-called "intermediate" pieces;

- the position of the finger or arm with respect to a spatial reference expresses and controls in analog manner - e.g. through a drive - the position of the tool;

- the tool is displaceable on/along the table through a horizontal linear guide mounted on the table.

In the text terms as above, below, lower, horizontal, etc. are referred to a press as in use. The advantages of the invention will be better clarified by the following description of a preferred embodiment, illustrated in the attached drawing wherein:

fig. 1 shows a bending press and a block diagram of the electronic control.

In the figures same numbers indicate equal parts, and the arrows indicate functional signal connections.

The system is used to control a bending press 10, which ordinarily has a lower table or beam 16 on which a vertically-movable table or upper beam 12 presses. On the tables 12, 16 tools U are mounted which get changed during processing and can be taken from a tool

storage (not shown). The tools (punches) U of the table 12 abut against dies (not shown) mounted on the table 16 to bend a piece.

On the table 12 a horizontal guide 14 is provided on which a well-known motorized organ or carriage 30 can slide linearly, which serves for gripping and displacement of the tools U. The carriage 30 of the example in the figure changes the tools U by taking them from the storage and setting them in position on the table 12, or the other way around.

A programmable electronic control unit 20 (or similar electronic circuit, e.g. a PLC or a microprocessor) controls the position and functions of the organ/carriage 30.

The control unit 20 is connected to a(n) (internal or external) data memory 40 and to a user interface, e.g. a touch-screen 70, from which it can receive control electrical signals and to which it sends data to generate images visible to the operator.

The control unit 20 drives the touch-screen 70 to display a first positional control window 60, and a second (optional) tool selection window 50.

The second window 50 includes a list or menu 52 of codes 54 corresponding to tools that can be taken from the storage. The user with a finger F selects a code 54, the control unit 20 detects it and controls the carriage 30 in order to move it to take from the storage the tool associated with the code.

The first window 60, intended for positioning a tool U on the table 12, comprises a, e.g. linear, reference 62, a slider 64 movable with respect to the reference 62 and preferably some buttons 66. The reference 62 is e.g. a line or strip to evoke the guide 14, and optionally comprises signs to indicate the end-of-travel limits of the carriage 30 on the guide 14. The cursor 64 indicates the current tool position on the guide 14.

By moving the cursor 64 along the reference 62 with the finger F, the user controls the position of the carriage 30 (and therefore of the tool) along the guide 14. For this purpose, the control unit 20

- detects, through the touch-screen 70, the position of a finger of the operator in the act of moving the cursor 64,

- interprets the dynamics thereof and the relative position with respect to the reference 62, and

- drives the carriage 30 so that it replicates the same relative position with respect to the guide 14.

When the tool carried by the carriage 30 is in the desired position, the operator presses a button 66 to save its position. The control unit 20, detected this action of the operator on the touch-screen 70, stores in the memory 40 a numeric data representing the linear coordinate of the carriage 30 with respect to the guide 14. By repeating the operation for many tools said second positional database forms in the memory 40.

VARIATIONS:

to ease a precise positioning of the tool on the guide 14, the control unit 20 can e.g. generate on the display of touch screen 70 a second reference such as the 62 to which is associated a second slider such as the 64. This second group of images can be used for fine positioning of the tool, representing a segment corresponding to a neighborhood of the tool (i.e. the fraction of the guide 14 that is a bit before and a bit beyond the current tool position). Or, again for the fine positioning of the tool, there may be a function of magnification or scale change on the first reference 62, so that the action on the slider 64 is relative to the neighborhood as defined above.