Patent Grant
9931685
The present invention relates to a tube bending machine comprising a bending head and an automatic loading system arranged to load a tube to be bent on the bending head. According to a further aspect, the present invention relates to a method for automatic loading of tubes on the bending head of a tube bending machine.
The term “tube” used in the following description and claims is to be intended as referring also to any other elongated blank, such as a bar or a profiled section. Likewise, the term “tube bending machine” is to be intended as referring also to a machine arranged to bend any other elongated blank, such as a bar or a profiled section.
Different kinds of automatic loading systems for tube bending machines are available on the market and in their simplest and cheapest form basically consist of an inclined plane on which the tube to be bent is caused to slide, the inclined plane being provided with stop members to stop the tube to be bent. The tube bending machines provided with such automatic loading systems are able to take a tube positioned on the inclined plane and to put down the worked tube on the ground by suitable control of the machine axes. In these tube bending machines, the position of the tube on the inclined plane is known in a transverse vertical plane (i.e. in a vertical plane perpendicular to the tube feed direction, or longitudinal direction), whereby the control unit of the machine is able to determine, on the base of suitable geometrical parameters of the machine, of the tube and of the inclined plane, the exact point where to position a loading tool (which may be either the bending tool normally present on the bending head of the machine or a tool specially designed for this purpose) to take the tube from the inclined plane. The tube is then made available to the bending head in an initial position, for instance the stop position at the bottom of the inclined plane defined by the aforesaid stop members, and is then moved by the bending head directly from this initial position to a final position where it can be clamped by a tube clamp or similar clamping member carried by the machine body. The automatic loading systems for tube bending machines currently available work well with tubes of circular cross-section, but not so well with tubes of non-circular cross-section. In case of tubes of non-circular cross-section, there is in fact the problem of properly orienting the tube relative to the loading tool in order to avoid damages to the tube resulting from the tube being clamped with a wrong orientation between the jaws of the loading tool or between the bending tool and the die. In order to avoid this problem, the automatic loading systems currently available on the market require a specific loading tool which can be oriented manually or a specific loading fixture designed so as to have exactly the same angle as the one existing between the loading tool and the axis of the tube to be loaded, which obviously involves problems in terms of time and costs for setting and mounting.
It is therefore an object of the present invention to allow the automatic loading also of tubes with a non-circular shape on the bending head of a tube bending machine.
This and other objects are fully achieved according to a first aspect of the present invention by virtue of a tube bending machine and, according to a further aspect of the present invention, by virtue of a method for automatic loading of tubes on the bending head of a tube bending machine.
Advantageous embodiments of the invention form the subject-matter, the content of which is to be intended as integral and integrating part of the following description.
In short, the invention is based on the idea of providing a tube bending machine comprising:
With the geometrical parameters of the machine, of the loading system and of the tube being known, the electronic control unit of the tube bending machine is able to define each time the path of the bending head in the transverse vertical plane and the rotation of the tube-carrying structure about its own axis of rotation, and hence to control the relating driving means accordingly, whereby with the bending head in the respective calculated initial position and with the tube-carrying structure in the respective calculated final position the tube carried by the tube-carrying structure is arranged in the free space of the clamping fixture of the bending head with the desired orientation relative to the clamping fixture and can therefore be correctly clamped by this latter. Unlike the prior art, the tube is not therefore directly moved by means of the bending head from the initial position to the final position on board of the machine, but is first moved by means of the tube-carrying structure from the initial position into an intermediate position (corresponding to the calculated final position of the tube-carrying structure and to the calculated initial position of the bending head) and then moved by means of the bending head from the intermediate position to the final position on board of the machine. Whereas the initial and final positions of the tube are fixed, the intermediate position is established from time to time by the electronic control unit.
With a loading system according to the invention, special tools or additional loading fixtures are no more required to ensure the desired orientation of the tube. Moreover, the tube can be automatically loaded either with tube bending machines able to perform both right-hand (i.e. in clockwise direction) and left-hand (i.e. in counter-clockwise direction) bending or with tube bending machines able to perform only one type of bending, i.e. only right-hand bending or only left-hand bending.
Preferably, the clamping fixture is formed by the die and by the bending tool already present on the bending head. There is therefore no need to use an additional clamping fixture.
Preferably, the two degrees of freedom of the bending head in the transverse vertical plane are a translational degree of freedom along a horizontal direction and a rotational degree of freedom about an axis perpendicular to the transverse vertical plane.
Preferably, the tube-carrying structure is spaced from the bending head in a direction perpendicular to the transverse vertical plane, thereby allowing the bending head to move freely in that plane with no risk of collisions with said structure. In this connection, the tube-carrying structure is provided with a feeding device arranged to move the tube carried by the tube-carrying structure towards the bending head, so as to allow the bending head to take the tube carried by the tube-carrying structure when this latter is in the calculated final position.
Further features and advantages of the present invention will appear more clearly from the following detailed description, given purely by way of non-limiting example with reference to the appended drawings, in which:
With reference first to
The tube bending machine 10 is also provided with first driving means arranged to move the above-mentioned parts of the machine, and therefore to move in particular the bending head 14 in the transverse vertical plane by controlling both the rotation of the bending head 14 about the axis of rotation X1 and the translation of the body 12 along the direction Y, as well as with an electronic control unit arranged to control said first driving means according to suitable programmable operating logics. Both the first driving means and the electronic control unit are of per-se-known type and will not therefore be described in further detail.
Again with reference to
According to the invention, the tube bending machine 10 further comprises a tube-carrying structure 36 arranged to receive each time a tube T from the loading device 28 (in the illustrated example, arranged to receive each time a tube T at the bottom of the inclined plane 32) and to move it towards the bending head 14 of the tube bending machine 10 by causing it to rotate about an axis of rotation X2 perpendicular to the transverse vertical plane (hence, in the present case, an axis of rotation parallel to the axis of rotation X1 of the bending head 14), so as to place it in a position such that it can be taken by the bending head 14. In the illustrated example, the tube-carrying structure 36 consists of at least two arms or levers rotatably supported by the support frame 30 about the axis of rotation X2. Each arm has, in a free end portion thereof (i.e. in a portion opposite to the portion in which the arm is hinged to the support frame 30), a seat 38 adapted to receive a tube T and a locking member (not shown as it is of per-se-known type) movable between an open position, in which the tube T can be inserted into the seat 38 and drawn out from it, and a closed position, in which the tube is locked inside the seat. The seat 38 is defined for instance by a pair of straight sides arranged at a right angle.
The tube-carrying structure 36 is preferably provided with a cylinder 40 (
The loading device 28 provided with the inclined plane 32 might also be replaced by any other kind of device adapted to put each time a tube T to be bent on the tube-carrying structure 36. The loading device might even be omitted, in which case the operation of putting the tube to be bent on the tube-carrying structure would be performed manually by an operator.
Second driving means (of per-se-known type and hence not described in further detail) are associated to the tube-carrying structure 36 and are arranged to cause the tube-carrying structure to rotate about the axis of rotation X2 between an initial position, in which the tube-carrying structure is able to receive a tube T, and a final position, and to move the locking members of the tube-carrying structure between the above-mentioned open and closed positions.
Also the second driving means (associated to the tube-carrying structure 36), beyond the first driving means (associated to the body 12 and to the bending head 14 of the tube bending machine 10), are controlled by the electronic control unit of the tube bending machine. In this connection, according to the invention the electronic control unit of the tube bending machine 10 is arranged to calculate, on the base of suitable geometrical parameters of the machine itself, of the tube-carrying structure 36, of the loading device 28 (if any) and of the tube T to be worked, the final position of the tube-carrying structure 36 and an initial position of the bending head 14 in the transverse vertical plane such that with the tube-carrying structure 36 in said final position and with the bending head 14 in said initial position the tube T carried by the tube-carrying structure 36 is placed in the free space defined by the clamping fixture of the bending head 14 (in the illustrated embodiment, the free space existing between the tool 26 and the die 24), with the clamping fixture in the open position, and can then be locked by the clamping fixture to be taken by the bending head 14 and brought by this latter in a final position on board of the machine to be clamped here by the tube clamp 13. The movements of the bending head 14 and of the tube-carrying structure 36 are calculated by the electronic control unit of the tube bending machine 10 so as to ensure that the tube T is positioned in the free space defined by the clamping fixture (free space between the die 24 and the tool 26) with the desired orientation, and can then be clamped between these two components of the clamping fixture with no risk of being damaged. In this connection, the expression “desired orientation” is to be intended, in view of the present invention, as referring to an orientation of the tube-carrying structure 36 (and hence of the tube T carried by it) relative to the bending head 14 in the transverse vertical plane such that the profile of the cross-section of the tube T forms a given angle with the profiles of the contact surfaces of the two components of the clamping fixture (the die 24 and the tool 26, in case of use of the bending fixture as clamping fixture, or the clamping jaws, in case of use of an additional clamping fixture). Once the movements to be imparted to the bending head 14 and to the tube-carrying structure 36 have been calculated, the electronic control unit suitably controls the first and second driving means in order to obtain the desired movements. The movement of the bending head 14 and the movement of the tube-carrying structure 36 can take place either in sequence (first the movement of the bending head 14 and then the movement of the tube-carrying structure 36 or vice versa) or at least partially simultaneously.
A tube bending machine provided with an automatic loading system according to the present invention allows therefore to place each time a tube to be bent with the desired orientation on the bending head, irrespective of the shape of the cross-section of the tube and without requiring the use of special tools or loading fixtures. In this connection,
Finally,
The automatic loading of a tube T on the bending head 14 of the tube bending machine 10 is therefore carried out with the following steps:
The loading of the tube comprises therefore a first step in which the tube is moved, by rotation of the tube-carrying structure about its own axis of rotation from the respective initial position to the respective final position calculated by the electronic control unit, from the respective initial position (for instance the stop position at the bottom of the inclined plane, if any) to a respective intermediate position, and a second step in which the tube is moved by means of the bending head from the respective intermediate position to a respective final position to be clamped by the tube clamp.
In the light of the above description, the advantages which can be obtained with a tube bending machine provided with an automatic loading system according to the present invention are evident.
First of all, the tube to be bent can be positioned on the bending head of the tube bending machine with the desired orientation with no need to add a special tool or loading fixture. The invention allows to load automatically a tube both on a machine able to perform both types of bending, i.e. right-hand bending and left-hand bending, and on a machine able to perform only one type of bending. In case of a tube of rectangular cross-section, the tube can be loaded automatically to be bent both in the “upright bending” configuration and in the “laid down bending” configuration, also with no need of a special tool or loading fixture. The invention allows to take into account automatically, by calculating in advance the movements of the tube-carrying structure and of the bending head, possible changes in the geometrical parameters of the bending head, of the tube-carrying structure and/or of the tube to be loaded, as well as possible changes in the orientation of holes or welding beads present on the tube to be loaded.
Naturally, the principle of the invention remaining unchanged, the embodiments and the constructional details may vary widely with respect to those described and illustrated purely by way of non-limiting example.
| Number | Date | Country | Kind |
|---|---|---|---|
| TO2010A0491 | Jun 2010 | IT | national |
This application is a Divisional of U.S. patent application Ser. No. 13/154,024, filed 6 Jun. 2011, which claims benefit of Serial No. TO2010A000491, filed 10 Jun. 2010 in Italy and which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications.
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| 4311031 | Schwarze | Jan 1982 | A |
| 4388039 | Schwarze | Jun 1983 | A |
| 5901596 | Tetzloff et al. | May 1999 | A |
| 5927126 | Biella | Jul 1999 | A |
| 6434993 | Broggi et al. | Aug 2002 | B1 |
| 6694794 | Crippa | Feb 2004 | B2 |
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| Number | Date | Country |
|---|---|---|
| 0191936 | Dec 2001 | WO |
| Entry |
|---|
| Extended European Search Report for corresponding European Patent Application No. 11169126.7 dated Nov. 21, 2011. |
| Number | Date | Country | |
|---|---|---|---|
| 20160375481 A1 | Dec 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13154024 | Jun 2011 | US |
| Child | 15261097 | US |
