The invention relates to a tool machine, in particular an improved bending press machine.

WO2016/063579 and EP1 160024, here taken as an example of the technology field of interest, disclose a press bending machine and relevant tool storage unit equipped with a mechanism for moving the tools.

The electronic control of the press determines from time to time which tool to remove from the storage unit and where to place it on the pressing table. A moving member hooks the tool in the storage unit, pulls it out and mounts it on the press; or from the press the tool is brought back in the storage unit no longer is needed. It is understood that the position of each tool relative to the carrying frame of the storage unit must be known in advance and with great precision.

Bending press machines' manufacturers provide a pre-assembled tool storage unit and a management software already equipped with a positional database for those tools. This ends up for the user of the press in a big and uncomfortable constraint: not being able to change the composition of the tool storage unit because their position in the storage unit is fixed and predetermined.

The poor flexibility of the storage unit is unfortunately accompanied by other disadvantages, the worst of which being the risk of jamming or machine-stops if a tool moves accidentally within the storage unit and/or the mobile member searches for it in a location indicated in the database that it is wrong.

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

Another object is to make a press bending machine and a method that allow improved, in particular more flexible, management of the tool storage unit, in particular by simplifying the tool management in the storage unit.

A first aspect of the invention is a localization method of a tool, contained in a tool-holder storage unit associated to a bending press, for directing a pick-up member onto said tool to move it from the unit towards the press, or vice versa, via a temporary coupling to a suitable connecting portion in the tool, comprising the steps of

detecting by a sensor the position of the tool, and

calculating tool connection portion's position by processing a signal emitted by the sensor.

Therefore, having to create a database of fixed positions for the tools is avoided, since the position of each tool to be picked up is calculated before or during the withdrawal and is not stored a priori in a database.

In the following, variants of the method to be used alone or in combination are described.

According to a preferred variant of the method, the position of the connecting portion of the tool to be taken is calculated in real time during a path that the pick-up member travels to withdraw the tool itself.

Thus, the position of each tool to be picked up is calculated very quickly and delays due to calculation are reduced, thereby speeding up the tool's withdrawal.

Preferably, to simplify the processing and reduce processing and machining time, the method provides the phases of

detecting by a sensor the position of a positional reference present on the tool, and

from the reference's coordinates, calculating the position of the connecting portion.

Preferably, the method provides the step of equipping the pick-up member with said sensor.

By moving the pick-up member near or towards the tool to be picked up. simultaneously the tool and the sensor are made to get closer to each other, with the advantages of

increasing the positional detection accuracy,

simplifying the system's structure (these machines have narrow spaces and it is less difficult to mount a sensor not far from the tool to be picked up),

ensuring a constant positional detection accuracy for all the tools. Also, it is preferable to use only one sensor for all the tools, another advantage.

In particular, the method provides for

moving the pick-up member equipped with said sensor toward or near the tool to be withdrawn until the sensor indicates that a tool's edge is reached, e.g. the edge closest to the pick-up member, and

advancing from the current position the pick-up member, in the same direction, by a linear segment corresponding to the offset.

More particularly, the method further provides that said step of advancing the pick-up member in the same direction comprises the steps of:

detecting the position of the pick-up member when said sensor signals that the edge of said has been reached;

calculating a final position of the pick-up member by adding to the current position of the pick-up member an offset,

moving the pick-up element to the final position and optionally hooking the tool.

A variant of the method comprises the steps of

(a) moving the pick-up member by a distance corresponding to the calculated offset,

(b) verifying at that point the presence of the connection portion, in the negative case, calculating or using a new offset value and repeating step (a) .

Another aspect of the invention regards a system comprising:

a press bending machine and an associated tool-holder storage unit, a pick-up member for taking a tool in order to move it from the storage unit towards the press, or vice versa, via a temporary coupling to a suitable connecting portion in the tool,

a sensor for detecting the position of the tool, and

a processing unit for calculating the position of the tool's connecting portion from the signal emitted by the sensor.

Another aspect of the invention regards a tool-carrier storage unit associable to a press bending machine, comprising: a pick-up member for taking a tool in order to move it from the storage unit towards the press, or vice versa, via a temporary coupling to a suitable connecting portion on the tool,

a sensor, mounted on the pick-up member, for

- detecting the tool's position, and

- sending to a processing unit the detected signal.

Another aspect of the invention regards a bending press comprising: a pick-up member for taking a tool in order to move it from the a tool- holder storage unit towards the press, or vice versa, via a temporary coupling to a suitable connecting portion on the tool,

a processing unit configured to calculate the position of the tool's connecting portion from a signal emitted by a sensor able to detect the position of the tool.

In all aspects and/or variants of the invention, the following advantageous options apply:

- said sensor is generally a sensor able to detect the presence of a body, or via interaction at a distance or by direct contact. It can be e.g. an IR sensor, a camera, a photocell, an RFID reader, a laser emitter, a capacitive or inductive sensor, a proximity sensor, an ultrasonic or waves electromagnetic transceiver, a touch probe, a sensitive edge to direct contact (such as a presence probe); a pressure detector (like a strain gauge or a load cell) , or an antenna; and / or

- the sensor is mounted on the pick-up member, or on the press, or at a remote point away from the press and the pick-up member; and/ or - the term real time indicates the simultaneity between the determination or calculation of said connection portion and the movement of the pick-up member in proximity and/or toward the tool to be picked; and/ or

- the positional reference on the tool can be any kind of position indicator, e.g. consisting of a portion of mass of the tool (such as a pin, one a cavity, an edge, a relief or a groove), or consisting of an object applied to the tool, such as a label, an RFID tag, a dowel, a screw or a pin, a tab, a mirror or a reflective part, an antenna, a cam, etc. Preferably the positional reference consists of an edge or rim of the tool, thereby any alteration of the latter being unnecessary and thus establishing a simple but rigorous localization rule for all of tools; and / or

- the phase of calculating the position of the connection portion and/ or the processing of the signal emitted by the sensor is preferably made by means of instructions of a software program executed by a microprocessor. The microprocessor may be aboard the press or aboard the storage unit, in particular aboard the pick-up member. The calculation is performed on digital data, corresponding to spatial coordinates; and/or - terms like vertical and horizontal are referred to the storage unit or tool as in use; and/ or

- the offset can be a positive or negative quantity; and/or

- the offset is preferably a constant quantity for all the tools; and/ or

- said step of adding the offset comprises addition and/ or subtraction; in particular operations performed by a processing unit (an analog electronic circuit and/ or a microprocessor or DSP on digital data) . Such digital data are e.g. the result of an analog/ digital conversion of an electrical signal output by said sensor or a positional digital value emitted by said sensor; and / or

- said connection portion preferably comprises one or more holes present in the tool's body, wherein the holes are engageable by corresponding pins or clamps present on pick-up member, which preferably comprises a clamp or a head equipped with protruding pins; and/or

. the tool storage unit is a device that can be either integrated inseparably in the bending press's structure or a self-contained accessory that can be coupled to, but is structurally independent and completely detachable from, the press bending machine; and/ or

- the storage unit preferably comprises frames comprising horizontal guides, vertically offset from each other and of equal length , inside which there are slidingly hanged or supported the tools. As options: said guides of all the frames are parallel to each other, and / or the guides of a frame lie in one same vertical plane and/or are horizontally spaced from the guides of the other frames. In other words, the guides and the tools of a frame are arranged in a plane being vertical and parallel to the planes that contain the guides and the tools of adjacent frames; and/or

- each frame is movable horizontally on the tracks and can be vertically raised by a lifting drive (with respect to the tracks) ; and / or

- the tool storage unit comprises a horizontal guide segment, e.g. fixed, for the tools. Any one of the guides can be raised and aligned to such segment, which serves as a bridge and extension between any of the raised guides and the housings in the pressing tables to accommodate the tools. Thus, any tool supported by any guide can be aligned with the segment and pushed (by the pick-up member) in the segment's guide to end up on a press's table. For this purpose the press is preferably equipped with a horizontal guide mating with the guide segment to allow the translation of the pick-up member from the storage unit to a press's table and viceversa; and/ or

- the step of moving the pick-up member preferably comprises, or consists only of, a linear translation motion. Preferably, the translation occurs in front of one or more aligned tools, so as to be able to reach them all; and/ or

- by position of the pick-up member it is also meant its conversion into analog electric signal or into a digital data, so that it can be managed by an electronic analog circuit and/ or a microprocessor or DSP;

- a processing unit, e.g. an analog electronic circuit and/or a microprocessor or DSP, is installed on the bending press, or on the pick-up member or on the storage unit, is programmed to perform and/or manage one or each of the method steps as defined or described here.

Further characteristics and advantages of the invention will be more apparent from the description of preferred embodiments, illustrated in the accompanying drawing, in which:

fig. 1 shows a three-dimensional view of a bending press;

fig. 2 shows an enlarged view of the circle C2 of FIG. 1;

Fig. 3 shows a three-dimensional view of another bending press;

fig. 2 shows an enlarged view of the circle CI of FIG. 3;

fig. 5 shows a conceptual diagram. In the figures, same numbers indicate equal parts; and to not crowd the figures some references are not repeated. The components are described as in use.

A press 10 (FIG. 1) comprises a lower table or cross member 14 on which a vertically movable table or upper cross member 12 presses. On the table 12 tools U (punches) are mounted which abut against dies 16 mounted on the table 14.

On the table 12 there is provided a horizontal guide 20 on which a member or carriage 30 can slide for picking-up and displacement of the tools U, which are changed during machining and can be withdrawn from a storage unit (not shown) next to the press 10. A electronic programmable control unit (not shown) controls the carriage or member 30.

Referring to fig. 2, the tool U hanging from the table 12 can be seen while it is picked-up by the member 30. The tool U comprises at the center holes 52, e.g. two vertically aligned holes. The carriage 30 comprises a proximity sensor 40, e.g. mounted on a bracket 42 having a protruding portion 44 to move the sensor 40 closer to the tool U.

The sensor 40 allows positioning the carriage 30 in front of (axially) the holes 52 for engaging them with pins and thereby hooking the tool U to move it.

See fig. 5, which schematically shows the tool U of Fig. 2 about to be picked-up. The carriage 30 moves to the left until the sensor 40 detects the nearest edge or rim 50 of the tool U. At this point, the sensor 40 sends a signal to the control unit which at the current position of the carriage 30 adds a horizontal offset S necessary to reach the holes 52. In the example it is assumed that the pins engaging the carriage 30 are aligned with the sensor 40, even if not necessary. It's possible to have a different position of the pins or holes 52 by changing the value of S. When the carriage 30 has traveled the additional distance S, it activates the pins aboard, hooks the tool U and then can move it elsewhere.

The value of S is advantageously constant, since the holes 52 of all the tools U are preferably made at the same distance S from the edge 50. The system can easily handle tools with holes 52 in different positions (e.g. for tools of different sizes), it is enough to use two or more increasing values for S, here called S I <S2 < Sn. The carriage is moved by a distance S I, and if it does not detect the holes 52 (e.g. via another sensor or after a failure in the hooking), it is moved by a distance S2, and so on, until the holes 52 are eventually located.

Figures 3 and 4 illustrate another application of the system.

The pick-able tool not only is a punch but also a so-called adapters (or intermediate parts) 60 (a piece mounted on the table 12 serving as a base for a punch). Sensor 40, in this case preferably a proximity meter, as before (see Figure 5) manages to locate the position of the adapter 60, which to facilitate the action of the sensor 40 comprises a cam or dowel 62 mounted or screwed on a rim. The adapter 60 comprises holes 52 like as the tool U, therefore is moved in the same way by the carriage 30.