JP2018144090A - Press brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press brake preventing a safety device from erroneously detecting an obstacle except an invading object as the invading object on both of front sides and depth sides of the positions of a punch and a die.SOLUTION: A safety device (a projector 30 and a light receiving unit 40) detects an invading object invading between a punch 14 and a die 24 and stops lowering of an upper table 10. The safety device has a front side monitoring region and a depth side monitoring region for monitoring invasion of the invading object on each of a front side and a depth side of a movement path of the punch 14 when the punch 14 lowers toward the die 24. Ranges in which the front side monitoring region and the depth side monitoring region are moved according to the lowering of the upper table 10 are defined as a front side search range and a depth side search range, respectively. The safety device invalidates the detection of the invading object by the front side monitoring region or the depth side monitoring region when it is detected that an obstacle interferes with the front side search range or the depth side search range by preliminarily executed simulation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a press brake including a safety device.

  The press brake includes an upper table on which a punch is mounted and a lower table on which a die is mounted. The press brake lowers the upper table to the lower table, and bends the workpiece, which is a metal material, between the punch and the die. When bending a workpiece, the press brake detects that an intruder such as a human hand has entered the bending area in order to prevent human hands from entering the area where the punch descends. A safety device that stops operation is provided.

  As one of the safety devices, there is a so-called laser-type safety device that stops the bending operation when an intruder blocks the laser light as described in Patent Document 1.

JP 2006-116574 A

  In a press brake safety device, if an intruder that intrudes inadvertently interrupts the laser beam, the bending process is stopped while an object other than an intruder such as a bent workpiece interrupts the laser beam. In some cases, it is necessary not to stop the bending operation.

  Patent Document 1 describes that when a workpiece bent on the front side of the front-rear direction position of the press brake where the punch and the die are located blocks the laser beam, the bending operation is not stopped. ing.

  However, in the safety device described in Patent Document 1, it is not considered that obstacles other than the intruding object block the laser beam on the back side of the punch and die positions. If the safety device erroneously detects an obstacle that is not an intruder as an intruder and the press brake stops operating, an operation for operating the press brake again is required, which reduces productivity.

  In the present invention, the safety device does not erroneously detect an obstacle other than the intruding object as an intruding object on both the front side and the back side of the punch and die positions, and the safety device is bent when the intruding object is detected. An object of the present invention is to provide a press brake capable of stopping the machining operation.

  The present invention relates to an upper table for holding a punch, a lower table for holding a die for machining a workpiece in cooperation with the punch, an actuator for lowering and raising the upper table, and controlling the actuator And a safety device that controls the control device so as to stop the descending of the descending upper table by detecting an intruder entering between the punch and the die. The apparatus monitors the intrusion of an intruder that descends as the upper table descends on the front side and the back side of the punch movement path when the punch descends toward the die. And the back side monitoring area, and the range in which the front side monitoring area and the back side monitoring area move as the upper table descends, When the front side search range and the back side search range on the front side of the moving path are set, the safety device detects the obstacle in the front search range or the back side by a simulation executed in advance in each processing step. Provided is a press brake configured to invalidate detection of an intruder by the front side monitoring area or the back side monitoring area when it is detected that interference with a search range is detected.

  According to the press brake of the present invention, the bending operation is stopped when the safety device detects an intruding object without stopping the bending operation even when the safety device detects an obstacle other than the intruding object. Can be made.

It is a figure showing a schematic structure of a press brake of one embodiment. It is a block diagram which shows the specific structure of the safety device with which the press brake of one Embodiment is provided. It is a figure which shows the front side monitoring area | region, the center monitoring area | region, and the back side monitoring area | region set to the safety device. It is a figure which shows the state which the front side monitoring area | region, the center monitoring area | region, and the back side monitoring area | region descend | fall as the upper table descends. It is a figure which shows the front side search range and back side search range which are formed with the fall of a front side monitoring area | region and a back side monitoring area | region. It is a figure which shows the example which the side flange of a workpiece | work interferes with the front side search range. It is a figure which shows the example which a back gauge interferes with the back side search range. It is a figure which shows the example which sets the retreat position to the upper part of the upper table at the time of completion | finish of the present machining process in consideration that an obstacle interferes with the front side search range or the back side search range in the next machining process. .

  Hereinafter, a press brake according to an embodiment will be described with reference to the accompanying drawings. First, a schematic configuration of the press brake will be described with reference to FIG. The press brake includes an upper table 10 and a lower table 20. The upper table 10 is configured to move up and down by hydraulic cylinders 11L and 11R provided on the left and right.

  Actuators 12L and 12R drive hydraulic cylinders 11L and 11R, respectively. The actuators 12L and 12R include, for example, a bidirectional rotary pump 121 and a motor 122 that rotates the bidirectional rotary pump 121 forward or backward.

  When the press brake control device 50 controls the motor 122 to rotate the motor 122 in the normal direction, the bidirectional rotary pump 121 can rotate in the normal direction to lower the hydraulic cylinders 11L and 11R. When the press brake control device 50 controls the motor 122 to reverse the motor 122, the bidirectional rotary pump 121 can reverse and raise the hydraulic cylinders 11L and 11R. The press brake control device 50 can be configured by an NC device.

  The linear encoders 13L and 13R detect the position of the upper table 10 in the vertical direction. The position information (stroke of the upper table 10) detected by the linear encoders 13L and 13R is supplied to the press brake control device 50 and a safety control unit 42 described later. The press brake control device 50 controls the position of the upper table 10 in the vertical direction based on the position information.

  The position information of the upper table 10 may not be supplied to the safety control unit 42, and the press brake control device 50 may supply the position information to the safety control unit 42.

  An upper mold holder (not shown) is attached to the upper table 10, and a lower mold holder (not shown) is attached to the lower table 20. A punch 14 is mounted on the upper mold holder, and a die 24 for processing the workpiece W in cooperation with the punch 14 is mounted on the lower mold holder. In this way, the upper table 10 holds the punch 14 and the lower table 20 holds the die 24. For example, the workpiece W, which is a flat plate material, is disposed on the die 24. When the upper table 10 is lowered, the workpiece W is sandwiched between the punch 14 and the die 24 and bent.

  Next, a schematic configuration of a safety device provided in the press brake of the present embodiment will be described. In FIG. 1, a projector 30 is mounted on the left side of the upper table 10 via an arm 15L. A light receiving unit 40 including a light receiver 41 and a safety control unit 42 is mounted on the right side of the upper table 10 via an arm 15R. The safety control unit 42 may be provided outside the light receiving unit 40. The projector 30 and the light receiving unit 40 constitute a safety device.

  The light projector 30 emits the laser light L30 toward the light receiver 41 so as to pass between the punch 14 and the die 24, and the light receiver 41 receives the laser light L30. When the upper table 10 is lowered, the light receiver 41 receives the laser beam L30 until the laser beam L30 is blocked by the workpiece W unless there is an intruder or an obstacle.

  The safety control unit 42 determines whether to stop the lowering of the upper table 10 depending on whether the light receiver 41 is in a light receiving state in which the laser light L30 is received or in a light blocking state in which the laser light L30 is not received. A signal Sstop is generated and output. The stop signal Sstop indicates that the descent of the upper table 10 is continued without being stopped if the value is “0”, and the descent of the upper table 10 is stopped if the value is “1”.

  After the value of the stop signal Sstop becomes “1” and the upper table 10 is stopped, the safety control unit 42 receives a value “0” as the stop signal Sstop when the light receiver 41 enters a light receiving state in which the laser beam L30 is received. Is output, and the lowering of the upper table 10 is permitted. When the light receiving device 41 continues to be shielded from not receiving the laser light L30, the upper table 10 may be allowed to descend again only under conditions that ensure safety, such as lowering the upper table 10 at a low speed.

  If the light receiver 41 receives the laser beam L30, the laser beam L30 is not blocked by an intruder such as a hand. Therefore, the safety control unit 42 outputs a value “0” as the stop signal Sstop. If the laser beam L30 is blocked by an intruder such as a hand while the upper table 10 is descending, the light receiver 41 does not receive the laser beam L30. Therefore, the safety control unit 42 outputs the value “1” as the stop signal Sstop.

  As will be described later, the safety control unit 42 is configured when the laser beam L30 is blocked by an obstacle (such as a work W or a movable part of a press brake) other than the intruding object and the light receiver 41 does not receive the laser beam L30. Is configured not to output the value “1” as the stop signal Sstop.

  When the laser light L30 has already been blocked by an obstacle (such as a workpiece W or a movable part of a press brake) other than the intruding object and the light receiver 41 has not received the laser light L30 at the time of starting the process. May output a value “1” as the stop signal Sstop.

  When the safety control unit 42 outputs the value “1” as the stop signal Sstop, the press brake control device 50 stops the lowering of the upper table 10 and interrupts the bending of the workpiece by the press brake.

  A specific configuration of the safety device will be described with reference to FIGS. 2 and 3. As shown in FIG. 2, the projector 30 includes a laser light source 301 and a collimator lens 302 that converts the laser beam of the diffused light emitted from the laser light source 301 into a laser beam L30 that is parallel light.

  The light receiver 41 has, for example, nine photodiodes Pd1 to Pd9. For convenience, numerals 1 to 9 are assigned to the photodiodes Pd1 to Pd9, respectively. A photodiode is an example of a photodetector. The photodiodes Pd1 to Pd9 individually detect the light receiving state and the light shielding state of the laser light L30. The light receiver 41 determines whether or not the laser light L30 is blocked based on the amplifiers Ap1 to Ap9 that amplify the output signals of the photodiodes Pd1 to Pd9 and the current value output from the amplifiers Ap1 to Ap9. And a discriminant value output unit 410 for outputting a value.

  FIG. 3 shows the arrangement of the photodiodes Pd1 to Pd9 when the light receiver 41 is viewed from the projector 30 with the upper table 10 positioned at the upper end (open end). The left side of FIG. 3 is the front side of the press brake, and the right side is the back side of the press brake.

  The photodiodes Pd <b> 1 to Pd <b> 3 are arranged in the vertical direction in front of the movement path of the punch 14 when the punch 14 descends toward the die 24. The photodiodes Pd4 to Pd6 are arranged in the vertical direction slightly behind the moving path. The photodiodes Pd4 to Pd6 may be arranged on the movement path. The photodiodes Pd7 to Pd9 are arranged in the vertical direction on the back side of the moving path.

  In the example shown in FIG. 3, the photodiodes Pd1, Pd4, Pd7, the photodiodes Pd2, Pd5, Pd8, and the photodiodes Pd3, Pd6, Pd8 are arranged at the same position in the vertical direction.

  The number of photodiodes arranged on the front side of the moving path, the number of photodiodes arranged on or slightly behind the moving path, and the number of photodiodes arranged on the far side of the moving path are limited to three. There may be two or four or more. The number of photodiodes that receive the laser beam L30 is not limited. The larger the number of photodiodes, the easier it is to detect intruders.

  The number of photodiodes placed on the front side of the moving path, the number of photodiodes placed on the moving path or slightly behind the moving path, and the number of photodiodes placed on the far side of the moving path are the same. It does not have to be. The arrangement of the photodiodes may be different on the front side of the moving path, on the moving path or slightly behind the moving path, and on the far side of the moving path.

  As an example, when the amplifiers Ap1 to Ap9 receive the laser light L30 and the amplifiers Ap1 to Ap9 output a current value of a predetermined level or higher, the discriminant value output unit 410 does not block the laser light L30. The discriminant value “0” is output. When any of the amplifiers Ap1 to Ap9 does not receive the laser beam L30 and the current value of a predetermined level or higher is not output from the corresponding amplifier among the amplifiers Ap1 to Ap9, the discrimination value output unit 410 outputs the laser beam L30. The discriminant value “1” indicating the interruption is output.

  The safety control unit 42 includes two central processing units (CPUs) 421 and 422. The discriminant value output from the discriminant value output unit 410 is supplied to the CPUs 421 and 422. In FIG. 2, the signal line from the discriminant value output unit 410 to the CPUs 421 and 422 is represented by one, but the CPUs 421 and 422 include discriminant values Det1 to Det9 based on the output signals of the photodiodes Pd1 to Pd9, respectively. Are supplied in parallel.

  The safety device includes a front side monitoring region 411 formed by the photodiodes Pd1 to Pd3, a central monitoring region 412 formed by the photodiodes Pd4 to Pd6, and a back side monitoring region 413 formed by the photodiodes Pd7 to Pd9. Have. In the press brake control device 50, information related to the mounting positions of the photodiodes Pd1 to Pd9 and information related to the front monitoring area 411, the central monitoring area 412 and the back monitoring area 413 are set.

  The front monitoring area 411 is an area in which intrusions such as human hands are monitored by the photodiodes Pd1 to Pd3 in front of the movement path of the punch 14. The central monitoring area 412 is an area where intrusion is monitored by the photodiodes Pd4 to Pd6 on the moving path or slightly behind the moving path. The back side monitoring region 413 is a region where intrusion is monitored by the photodiodes Pd7 to Pd9 on the back side from the movement path.

  As shown in FIGS. 4A to 4D, as the upper table 10 descends, the projector 30 (not shown here) and the light receiver 41 (front monitoring area 411, central monitoring area 412 and The back monitoring area 413) is lowered. FIG. 4A shows a state in which the same upper table 10 as in FIG. 3 is located at the upper end.

  The press brake control device 50 has information on the punch 14 and the die 24 such as the die height, and information on the work W such as the plate thickness. The press brake control device 50 sets the mute point Pmute at a predetermined distance short enough to prevent a human hand (finger) from entering from the upper surface of the work W arranged on the die 24. Information regarding the mute point Pmute is supplied to the CPUs 421 and 422. The mute point Pmute is set to a distance of about 6 mm from the upper surface of the workpiece W, for example.

  In FIG. 4C, since the photodiodes Pd3, Pd6, and Pd9 have passed the mute point Pmute, the CPUs 421 and 422 invalidate the photodiodes Pd3, Pd6, and Pd9. In FIG. 4D, since all the photodiodes Pd1 to Pd9 have passed the mute point Pmute, the CPUs 421 and 422 invalidate the photodiodes Pd1 to Pd9.

  The mute point Pmute is set so as not to stop the operation of the press brake even when the workpiece W blocks the laser beam L30.

  When the upper table 10 and the light receiver 41 are lowered as shown in FIGS. 4A to 4D, as shown in FIG. 5, the front side monitoring area 411 is lowered in front of the movement path of the punch 14 as shown in FIG. A front-side search range 4110 is formed, and a back-side search range 4130 is formed on the back side of the movement path of the punch 14 by the lowering of the back-side monitoring region 413.

  The front search range 4110 is a range in which the front monitoring area 411 moves, and the back search range 4130 is a range in which the back monitoring area 413 moves. However, in the present embodiment, since the mute point Pmute is set, the front search range 4110 is a range from the upper end of the front monitoring area 411 to the mute point Pmute when the upper table 10 is located at the upper end. It is. The back side search range 4130 is a range from the upper end of the back side monitoring region 413 to the mute point Pmute when the upper table 10 is located at the upper end.

  The press brake control device 50 executes a simulation in advance so that obstacles such as a movable part of the work W or the press brake interfere with the front search range 4110 or the back search range 4130 in each processing step of the work W. And whether or not the height of the obstacle is detected. The simulation result by the press brake control device 50 is supplied to and held by the CPUs 421 and 422.

  FIG. 6 shows a case where the workpiece W having the side flange Wsf is machined. The side flange Wsf of the workpiece W is a first example of an obstacle. The press brake control device 50 detects that the side flange Wsf interferes with the front search range 4110 by the simulation of the machining process shown in FIG. Further, the press brake control device 50 detects the height Hsf within the front side search range 4110 of the side flange Wsf. The CPUs 421 and 422 are set to a box bending mode that disables the detection of intrusion by the front monitoring area 411 in the processing step shown in FIG.

  Even if the CPUs 421 and 422 are set to the box bending mode, if the detected obstacle height does not match the predetermined height Hsf, the CPU 421 and 422 continue to detect the intruder entry by the front monitoring area 411. May be.

  In FIG. 6, the back gauge 60 (not shown in FIG. 1) is pressed against the back end of the workpiece W. The back gauge 60 is an example of a movable part of the press brake. The press brake control device 50 moves the back gauge 60 in accordance with the position where the back end of the workpiece W is positioned. When the back end of the workpiece W is pressed against the back gauge 60, the workpiece W is positioned and processed at an appropriate position in the front-rear direction. Here, the back gauge 60 does not interfere with the back side search range 4130.

  FIG. 7 shows a case where the workpiece W is machined by being protruded by a short distance to the back side from the die 24. The back gauge 60 is pressed against the back end of the workpiece W. Here, the back gauge 60 interferes with the back side search range 4130. The back gauge 60 is a second example of an obstacle. Since the press brake control device 50 is set with information about the back gauge 60 such as the height of the abutting member, the back gauge 60 interferes with the back side search range 4130 and the back side by simulation of the machining process. The height of the obstacle in the search range 4130 can be detected.

  In the processing step shown in FIG. 7, the press brake control device 50 detects that the back gauge 60 interferes with the back side search range 4130. The CPUs 421 and 422 are set to a back gauge mode in which the detection of the intrusion of the intruding object by the back side monitoring area 413 is invalidated in the processing step shown in FIG. In FIG. 7, since the workpiece W does not have the side flange Wsf, the workpiece W does not interfere with the front search range 4110.

  Even if the CPUs 421 and 422 are set to the back gauge mode, if the height of the detected obstacle does not coincide with the height of the obstacle given in advance, the detection of the intrusion of the intruder by the back side monitoring area 413 is detected. You may continue.

  When the side flange Wsf interferes with the front side search range 4110 as in FIG. 6 and the back gauge 60 interferes with the back side search range 4130 as in FIG. 7 in the predetermined processing step, the CPUs 421 and 422 are Set to box bending mode and back gauge mode.

  As described above, in the present embodiment, the safety device can detect whether or not obstacles having individual predetermined heights interfere with each other in the front search range 4110 and the back search range 4130. In the present embodiment, the safety device invalidates the detection of the intruder by the front monitoring area 411 when it is detected that an obstacle with a predetermined height interferes with the front search range 4110. In the present embodiment, the safety device invalidates the detection of the intruder by the back side monitoring area 413 when it is detected that an obstacle with a predetermined height interferes with the back side search range 4130.

  When the side flange Wsf interferes with the front search range 4110, the CPUs 421 and 422 set the box bending mode and the back gauge mode to detect the intrusion of intruders by both the front monitoring area 411 and the back monitoring area 413. It may be disabled. When the back gauge 60 interferes with the back side search range 4130, the CPUs 421 and 422 detect the intrusion entry by both the front side monitoring area 411 and the back side monitoring area 413 by setting the box bending mode and the back gauge mode. May be disabled.

  Obstacles that may interfere with the front search range 4110 or the back search range 4130 are not limited to the side flange Wsf and the back gauge 60. A molded product such as burring formed on the workpiece W may become an obstacle. When a molded product such as burring is formed on the workpiece W, the press brake control device 50 executes a simulation based on the information on the workpiece W, so that the molded product interferes with the front search range 4110 or the back search range 4130. Whether or not to do so can be detected.

  Further, in two continuous machining steps, the obstacle interferes with the front search range 4110 or the back search range 4130 at the start of the next machining step, and the value “1” is output as the stop signal Sstop. In order to avoid this, the press brake control device 50 preferably retracts the upper table 10 upward as follows at the end of the current machining process.

  FIG. 8A shows a state in which the upper table 10 is retracted upward at the end of the current machining process. FIG. 8B shows the next machining step, and the side flange Wsf interferes with the front search range 4110 in the next machining step. In such a case, in the press brake control device 50, as shown in FIG. 8A, the front monitoring area 411 and the back monitoring area 413 are larger than the maximum height Hsf of the side flange Wsf in the front search range 4110. The upper table 10 is retracted upward so that the upper table 10 is also positioned upward.

  In this way, it is possible to avoid that the value “1” is output as the stop signal Sstop at the start of the next machining step and the operation of the press brake is stopped.

  The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the present invention.

10 Upper table 12L, 12R Actuator 14 Punch 20 Lower table 24 Die 30 Floodlight (safety device)
40 Light receiving unit (safety device)
50 Press brake control device (control device)
Pd1 to Pd9 Photodiode W Workpiece

The present invention relates to an upper table for holding a punch, a lower table for holding a die for machining a workpiece in cooperation with the punch, an actuator for lowering and raising the upper table, and controlling the actuator And a safety device that controls the control device so as to stop the descending of the descending upper table by detecting an intruder entering between the punch and the die. The apparatus monitors the intrusion of an intruder that descends as the upper table descends on the front side and the back side of the punch movement path when the punch descends toward the die. and it has a rear side monitoring area, the front of the front search than before Symbol movement path a distance to the front monitor area is moved by the upper table is lowered When the circumference, in each processing step, the simulation is performed in advance by the control device, when an obstacle that has been detected to interfere with the front search range, the intruder by the front monitor area When the detection is invalidated and the range in which the back side monitoring area moves as the upper table moves down is set as the back side search range on the back side from the moving path, in each processing step, by the control device in advance When the simulation to be executed detects that the back gauge pressed against the back end of the workpiece interferes with the back search range as an obstacle, the detection of the intruder by the back monitoring area is invalidated. providing a press brake, characterized in that it is configured to reduction.

Claims (6)

An upper table to hold the punch,
A lower table for holding a die for working a workpiece in cooperation with the punch;
An actuator for lowering and raising the upper table;
A control device for controlling the actuator;
A safety device that detects an intruder entering between the punch and the die and controls the control device to stop the descending of the descending upper table;
With
The safety device monitors the intrusion of intruders that descend as the upper table descends on the front side and the rear side of the punch movement path when the punch descends toward the die. A monitoring area and a back monitoring area;
When the range in which the front side monitoring area and the back side monitoring area move as the upper table descends is set as the front side search range and the back side search range on the far side from the moving path, respectively, the safety device Intrusion by the front side monitoring area or the back side monitoring area when an obstacle is detected to interfere with the front side search range or the back side search range by a simulation executed in advance in each processing step. A press brake characterized by being configured to disable detection of an object.   The safety device detects whether or not an obstacle with a specific predetermined height interferes with each of the front search range and the back search range, and the obstacle with a predetermined height interferes with the front search range. The detection of the intruder by the front monitoring area is invalidated when it is detected, and the intruder by the back monitoring area is detected when it is detected that an obstacle with a predetermined height interferes with the back search range. The press brake according to claim 1, wherein the press brake is configured to invalidate detection of the press. The safety device is provided with a mute point that invalidates detection of an intruding object by the front monitoring area and the back monitoring area at a predetermined distance from the upper surface of the workpiece arranged on the die. And
The front-side search range and the back-side search range are ranges from the upper end of the front-side monitoring region and the back-side monitoring region to the mute point when the upper table is positioned at the upper end. The press brake according to claim 1 or 2.   The safety device invalidates detection of an intruder by the front monitoring area when it is detected that the side flange of the workpiece interferes with the front search range using an obstacle as a side flange. The press brake of any one of 1-3.   The safety device invalidates detection of an intruder by the back side monitoring area when it is detected that the back gauge pressed against the back side end of the workpiece interferes with the back side search range. The press brake according to any one of claims 1 to 4, wherein:   When it is detected by a simulation executed in advance in the next machining step of the current machining step that an obstacle interferes with the front search range or the back search range, the control device The actuator is so arranged that the front side monitoring area and the back side monitoring area are located above the maximum height in the front side search range or the back side search range of the obstacle in the next machining step at the end of The press brake according to any one of claims 1 to 5, wherein the upper table is retracted upward by controlling the upper table.

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