JP3797718B2 - Press brake - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a press brake, and more particularly to a press brake equipped with a bending angle measuring device for measuring a bending angle of a workpiece to be bent.
[0002]
[Prior art]
Conventionally, when bending a plate-shaped workpiece using a bending machine such as a press brake, various bending data are input to the NC unit, and a driving die (punch) is input based on the input data. ) Is calculated, and bending is performed based on the calculation result. However, even if the amount of punch driving is controlled in this way, in actual bending, a desired bending angle is often not obtained due to variations in the plate thickness of the material and differences in various processing conditions. For this reason, various proposals have been made and put to practical use in which the bending angle of a workpiece is measured in-line during the bending process, and the driving amount is corrected based on the measured bending angle.
[0003]
By the way, as the bending angle measuring apparatus for measuring the bending angle of the workpiece as described above, various types such as a contact type or a non-contact type such as an optical type and a capacitance type are adopted. However, all the bending angle measuring devices are usually fixed and provided at one central portion of the table supporting the die.
[0004]
[Problems to be solved by the invention]
However, when a long material is to be accurately bent by a single bending process, it is necessary to correct an angular error due to a change in the plate thickness or plastic characteristics in the longitudinal direction of the material, or a table or ram. Since it is necessary to correct the middle-opening phenomenon due to the deflection of the workpiece during bending, it is impossible to accurately measure the bending angle of the workpiece by simply providing a bending angle measuring device in one place as in the prior art. There's a problem. Similarly, in the case of a so-called step bend processing method in which a plurality of bending dies are attached to a long press brake and bending is performed while sequentially moving short materials in the left-right direction, as described above. An accurate bending angle of a workpiece cannot be obtained only by a bending angle measuring device fixedly attached at one place. In order to cope with such problems, it is conceivable to provide a plurality of bending angle measuring devices. However, simply installing a plurality of bending devices will increase the size of the device and provide support for bending work. End up.
[0005]
In order to solve such problems, the present invention makes it possible to move the bending angle measuring device along the longitudinal direction of the workpiece with a structure that does not interfere with the bending work, thereby measuring the bending angle of the workpiece. An object of the present invention is to provide a press brake capable of improving the accuracy.
[0006]
[Means for solving the problems and actions / effects]
In order to achieve the aforementioned object, a press brake according to the present invention is firstly
In press brakes that bend plate-like workpieces in cooperation with punches and dies,
A linear guide extending in the left-right direction below the die and on the front surface and / or rear surface of the table supporting the die;
A plurality of movable stands provided movably along the linear guide and mounted with an angle measuring device;
It is attached integrally to the lower part of each movable table, the length thereof is different from each other, and a bracket to which driving means for moving each movable table is attached to the lower end thereof ,
The plurality of movable platforms are provided on the same linear guide extending on the front surface or the rear surface of the table .
[0007]
In the present invention, by driving the driving means, the movable base is moved in the left-right direction along the linear guide via the bracket, whereby the angle measuring device mounted on the movable base is placed on the die. The workpiece is moved to a position facing a required portion of the workpiece, and the bending angle of the workpiece at that position is measured. Since the bending angle at any position of the workpiece can be measured in this way, it is possible to easily correct the angle error in the longitudinal direction of the material or the middle opening phenomenon due to the deflection of the table or ram. It is possible to easily measure the bending angle of the workpiece at the mold position. According to the present invention, since each carriage is mounted to the drive means via a bracket having different length thereof with each other, when moving independently an angle measuring device of the double number groups, multiple driving means Can be avoided, and the drive means can be effectively arranged at a position that does not interfere with the bending operation.
[0008]
In the present invention, the driving means may include sprockets respectively disposed on the left and right sides of the table, an endless chain that is hung around the sprockets, and a motor that drives the sprockets. Moreover, it is good also as what has the pulley each distribute | arranged to the both right and left sides of the said table, the endless timing belt hung around these pulleys, and the motor which drives the said pulley.
As another aspect, the press brake according to the present invention is secondly,
In press brakes that bend plate-like workpieces in cooperation with punches and dies,
A linear guide extending in the left-right direction below the die and on the front surface and / or rear surface of the table supporting the die;
A fixed ball screw juxtaposed to this linear guide;
A plurality of movable stands provided movably along the linear guide and mounted with an angle measuring device;
A bracket integrally attached to the bottom of each movable base;
A drive nut rotatably attached to the bracket and meshing with the ball screw;
A motor attached to the bracket and rotating the drive nut ;
The plurality of movable platforms are provided on the same linear guide extending on the front surface or the rear surface of the table .
Furthermore, the press brake according to the present invention is thirdly,
In press brakes that bend plate-like workpieces in cooperation with punches and dies,
A linear guide extending in the left-right direction below the die and on the front surface and / or rear surface of the table supporting the die;
A fixed rack juxtaposed to this linear guide;
A plurality of movable stands provided movably along the linear guide and mounted with an angle measuring device;
A bracket integrally attached to the bottom of each movable base;
A pinion rotatably attached to the bracket and meshing with the rack;
A motor attached to the bracket and configured to rotate the pinion ;
The plurality of movable platforms are provided on the same linear guide extending on the front surface or the rear surface of the table .
Here, the motor may be a pulse motor, a servo motor, an induction motor by timer control, or a hydraulic or pneumatic motor by timer control.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, specific embodiments of the press brake according to the present invention will be described with reference to the drawings.
[0010]
FIG. 1 is a front view of a press brake according to an embodiment of the present invention, and FIG. 2 is a side view of the press brake.
[0011]
The press brake according to the present embodiment includes a fixed table 1 and a ram 2 that is driven to move up and down against the table 1, and the upper surface of the table 1 is V-shaped via a die holding device 3. A die (lower die) 4 having a die groove is held, and a punch (upper die) 5 is attached to a lower portion of the ram 2 so as to face the die 4 via a punch holding device 6.
[0012]
A pair of side frames 7 and 8 are integrally provided at both ends of the table 1, and a support frame 9 is provided so as to connect the upper ends of the side frames 7 and 8. A plurality of (four in this embodiment) ram driving devices 10a, 10b, 10c, and 10d are attached to the support frame 9, and the ram 2 can swing freely at the lower ends of the ram driving devices 10a to 10d. It is connected to. Thus, the work inserted between the punch 5 and the die 4 is bent by raising and lowering the ram 2 by the operation of the ram driving devices 10a to 10d.
[0013]
Each of the ram driving devices 10a to 10d transmits the driving force to the ball screw 13 connected to the ram 2 via the timing belt 12 by using the AC servo motors 11a to 11d provided at the rear as a driving source. Thus, the rotational driving force of the servo motors 11a to 11d is converted into a moving force in the vertical direction to generate a pressing force on the workpiece.
[0014]
The vertical position of the ram 2 is detected by linear encoders (incremental encoders) 14a to 14d provided corresponding to the drive shaft positions of the ram drive devices 10a to 10d, and the detection data is input to the NC device. The servo motors 11a to 11d are feedback-controlled through servo amplifiers in accordance with the positions of the axes, and the brakes attached to the motor shafts of the servo motors 11a to 11d are controlled by a machine control device (sequencer). It has become. Here, the linear encoders 14a to 14d are supported by a correction bracket 17 configured by two side plates provided along the side frames 7 and 8 and a beam connecting the left and right side plates. Yes. With such a configuration, the linear encoders 14a to 14d can measure the absolute position of each axis of the ram 2 without being affected by deformation due to load changes of the side frames 7 and 8. The motor shafts of the servo motors 11a to 11d are provided with encoders (absolute encoders) 18a to 18d for detecting the current positions of the servo motors 11a to 11d. Each servo amplifier is controlled.
[0015]
The control device 20 including the NC device and the machine control device (sequencer) for controlling the ram driving devices 10a to 10d is attached to the side of the main body frame of the press brake, and is used for inputting bending data and the like. An operation panel 21 including a keyboard, a display for displaying various data, and various switches is suspended from a support frame 9 via a swingable arm 22. Further, a foot switch 23 for stepping operation is provided below the main body frame. In addition, an abutting device (back stop device) 24 for restricting the pushing position of the workpiece W to be bent is provided behind the table 1.
[0016]
In the press brake of the present embodiment, a total of six angle measuring devices 25 are provided below the die 4 and on the front and rear surfaces of the table 1 that supports the die 4, so that a total of six angle measuring devices 25 can move in the left-right direction. ing. Hereinafter, the detailed structure of the angle measuring device 25 and its moving mechanism will be described with reference to FIGS.
[0017]
A linear guide 26 extends in the left-right direction on the front and rear surfaces of the table 1, and a movable table 27 on which the angle measuring device 25 is mounted is movably provided along the linear guide 26. A bracket 28 is attached to the lower part of the movable base 27 downward, and a lower end portion of the bracket 28 is fixed to a timing belt 29. The timing belt 29 is wound around pulleys 30 and 30 which are arranged on both the left and right sides and are rotatably supported with respect to the surface of the table 1, and one pulley 30 is attached to the rear surface of the table 1 by a servo motor 31. The timing belt 29 is driven by being driven. The drive-side pulley 30 is attached to a front end portion of a transmission shaft 32 provided so as to penetrate the table 1 in the front-rear direction, and a pulley disposed on the front side of the table 1 at the rear end portion of the transmission shaft 32. 30 is attached. In this way, the pulleys 30 on the front side and the rear side of the table 1 are rotated by the drive of one servo motor 31, and the timing belts 29 and 29 on the front side and the rear side, as well as the movables on the front side and the rear side, respectively. The tables 27 and 27 are driven synchronously and moved along the linear guide 26.
[0018]
As shown in FIG. 6, the timing belts 29 provided corresponding to the respective angle measuring devices 25 are arranged so as to be offset from each other in the vertical direction, and left and right so that the servomotors 31 do not interfere with each other. The direction is also offset. In order to enable such a configuration, the three pairs of brackets 28 provided corresponding to the respective movable bases 27 are configured to have different lengths. With such a configuration, even if a plurality of angle measuring devices 25 are provided, the driving mechanism can be compactly gathered so as not to obstruct the bending operation.
[0019]
The angle measuring device 25 projects linear laser light on the outer surface of the workpiece W, captures the reflected light with a CCD camera, and measures the bending angle of the workpiece W by performing image processing on the captured image. To do. The angle measurement method is not limited to that of this embodiment, and various types can be used. In addition, what is shown with the code | symbol 33 in a figure is the energy supply cable support means which supplies energy to this angle measuring device 25. FIG.
[0020]
Since it is configured as described above, the three servo motors 31 provided on the rear surface side of the table 1 are driven and controlled, so that the front side three and the rear side three total six angle measuring devices 25 can be arbitrarily set. It is possible to freely move to the measurement position and to reliably measure the bending angle of the desired position of the workpiece W.
[0021]
In this embodiment, the angle measuring device 25 before and after the table 1 is moved in synchronization by one servomotor 31. However, different driving motors are used on the front side and the rear side of the table 1. An example is of course possible.
[0022]
In the present embodiment, the angle measuring device is arranged on the front side and the rear side of the table 1, but this angle measuring device is arranged only on either the front side or the rear side of the table 1. Also good. Further, in this embodiment, three angle measuring devices are provided on each of the front side and the rear side, but the radix of this angle measuring device can be changed as needed.
[0023]
In the present embodiment, the description has been given of the movable base 27 that is moved by the pulley 30 and the endless timing belt 29 that is wound around the pulley 30, but the sprocket is used instead of the pulley, and the chain is used instead of the timing belt. Even if each of them is used, the same actions and effects as described above can be obtained.
[0024]
FIGS. 8A and 8B show a partial cross-sectional view and a partial front view of a press brake according to another embodiment of the present invention.
[0025]
In this embodiment, as drive means for moving the movable base 27, a drive side gear 35 attached to the gear head 34 of the servo motor 31, a driven side gear 36 meshing with the drive side gear 35, and this driven side A configuration including a drive nut 37 provided integrally with the gear 36 and a fixed ball screw 38 meshing with the drive nut 37 is employed. With such a configuration, when the servo motor 31 is driven, the drive nut 37 is rotated via the drive side gear 35 and the driven side gear 36, and the drive nut 37 moves along the ball screw 38. As a result, the angle measuring device 25 is moved in the left-right direction along the linear guide 26.
[0026]
9 (a) and 9 (b) show a partial cross-sectional view and a partial front view of a press brake according to still another embodiment of the present invention.
[0027]
In the case of the present embodiment, as a driving means for the movable base 27, a rack 39 that is arranged in parallel with the linear guide 26 and fixed to the front and rear surfaces of the table 1 is attached to the bracket 28 so as to mesh with the rack 39. The structure provided with the pinion 40 and the servo motor 31 which is also attached to the bracket 28 so that this pinion 40 may be rotated is employ | adopted. With such a configuration, when the servo motor 31 is driven, the pinion 40 is rotated, and the pinion 40 is engaged with the rack 39 and moved, whereby the angle measuring device 25 is moved to the linear guide 26. Along the left-right direction.
[0028]
In each of the above embodiments, a so-called overdrive type press brake in which an upper die is attached to a ram (movable member) and a lower die is attached to a table (fixed member) has been described. Needless to say, the present invention can also be applied to a so-called underdrive press brake in which a lower die is attached to a member) and an upper die is attached to a table (fixing member).
[0029]
In each of the above-described embodiments, the AC servo motor and the ball screw are used as the drive source for the ram. However, a hydraulic unit and a cylinder can be used as the drive source.
[0030]
In each of the above-described embodiments, the case where the drive shaft of the ram is four axes has been described. However, the drive shaft may be three axes or five or more axes. Further, it goes without saying that the moving mechanism of the angle measuring device in each of the embodiments can be applied to a press brake that drives a ram with two axes.
[Brief description of the drawings]
FIG. 1 is a front view of a press brake according to an embodiment of the present invention.
FIG. 2 is a side view of the press brake of the present embodiment.
FIG. 3 is a partial rear view of the press brake of the present embodiment.
FIG. 4 is a view taken in the direction of arrow A in FIG. 3;
FIG. 5 is a partial cross-sectional view of the press brake according to the present embodiment.
FIG. 6 is a rear view showing a driving mechanism of the movable table.
FIG. 7 is a cross-sectional view showing a drive mechanism of a movable table.
FIG. 8 is a partial sectional view (a) and a partial front view (b) of a press brake according to another embodiment.
FIG. 9 is a partial sectional view (a) and a partial front view (b) of a press brake according to still another embodiment.
[Explanation of symbols]
1 Table 2 Ram 4 Die (lower mold)
5 Punch (upper die)
7, 8 Side frames 10a to 10d Ram drive devices 11a to 11d Servo motor 12 Timing belt 13 Ball screw 14a to 14d Linear encoder 17 Correction bracket 18a to 18d Encoder 21 Operation panel 25 Angle measuring device 26 Linear guide 27 Movable base 28 Bracket 29 Timing belt 30 Pulley 31 Servo motor 32 Transmission shaft 35 Drive side gear 36 Drive side gear 37 Drive nut 38 Ball screw 39 Rack 40 Pinion

Claims (5)

In press brakes that bend plate-like workpieces in cooperation with punches and dies,
A linear guide extending in the left-right direction below the die and on the front surface and / or rear surface of the table supporting the die;
A plurality of movable stands provided movably along the linear guide and mounted with an angle measuring device;
It is attached integrally to the lower part of each movable table, the length thereof is different from each other, and a bracket to which driving means for moving each movable table is attached to the lower end thereof ,
The plurality of movable platforms are provided on the same linear guide extending on the front or rear surface of the table .   2. The press brake according to claim 1, wherein the driving means includes a sprocket disposed on each of the left and right sides of the table, an endless chain wound around the sprocket, and a motor that drives the sprocket. .   2. The press according to claim 1, wherein the driving means includes pulleys respectively disposed on both left and right sides of the table, an endless timing belt wound around the pulleys, and a motor that drives the pulleys. brake. In press brakes that bend plate-like workpieces in cooperation with punches and dies,
A linear guide extending in the left-right direction below the die and on the front surface and / or rear surface of the table supporting the die;
A fixed ball screw juxtaposed to this linear guide;
A plurality of movable stands provided movably along the linear guide and mounted with an angle measuring device;
A bracket integrally attached to the bottom of each movable base;
A drive nut rotatably attached to the bracket and meshing with the ball screw;
A motor attached to the bracket and rotating the drive nut ;
The plurality of movable platforms are provided on the same linear guide extending on the front or rear surface of the table . In press brakes that bend plate-like workpieces in cooperation with punches and dies,
A linear guide extending in the left-right direction below the die and on the front surface and / or rear surface of the table supporting the die;
A fixed rack juxtaposed to this linear guide;
A plurality of movable stands provided movably along the linear guide and mounted with an angle measuring device;
A bracket integrally attached to the bottom of each movable base;
A pinion rotatably attached to the bracket and meshing with the rack;
A motor attached to the bracket and configured to rotate the pinion ;
The plurality of movable platforms are provided on the same linear guide extending on the front or rear surface of the table .

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