Patent Description:
In recent years, bending systems have become widespread in the field of sheet metal processing. Hereinafter, the configuration and the like of the bending system will be briefly described (see Patent Literature <NUM>).

The bending system includes a press brake that bends a workpiece. A bending robot that assists in bending the workpiece is provided between the press brake and a predetermined setting area that is arranged in front of the press brake. The bending robot includes a robot hand that holds the workpiece on a pallet set in the predetermined setting area. Further, above the predetermined setting area, a camera as an image pickup unit that picks up an image of the workpiece on the pallet from a vertically upper direction is provided. A first illumination unit that irradiates an image pickup area of the camera with an illumination beam is provided in the vicinity of the left side of the predetermined setting area. A second illumination unit that irradiates the image pickup area of the camera with an illumination beam is provided in the vicinity of the right side of the predetermined setting area.

The bending system includes a numerical control device that controls the press brake, a robot control device that controls the bending robot, and an image processing device that performs image processing to a picked-up image from the camera. The image processing device detects a location of the workpiece on the palette based on the picked-up image from the camera. Based on the detected location of the workpiece, the robot control device controls the bending robot such that the robot hand holds a predetermined portion of the workpiece. Therefore, even if the workpiece is not placed accurately at a predetermined position on the pallet, it is possible to sufficiently ensure the processing accuracy of the bending by appropriately operating the bending robot.

Note that as related prior arts, in addition to Patent Literature <NUM>, there are those shown in Patent Literatures <NUM> to <NUM>.

Now, in the conventional bending system, the camera is located above the predetermined setting area and is not sufficiently separated from the predetermined setting area. The two illumination units are located in the vicinity of the predetermined setting area and are not sufficiently separated from the predetermined setting area. As a result, in order to prevent a part of the bending robot and the workpiece held by the robot hand from interfering with the camera or the like, the operating range of the bending robot is limited, which often results in a case in which it is impossible to bend the workpiece. In other words, there is a problem that it is difficult to increase the degree of freedom of the processing of the bending system while sufficiently ensuring the processing accuracy of the bending.

A bending system according to a first embodiment of the present invention includes a bending robot provided between a press brake and a predetermined setting area arranged in front of the press brake, including a robot hand for holding a workpiece on a pallet set in the predetermined setting area, and configured to assist in bending the workpiece, and an image pickup unit provided above and anterior to the predetermined setting area and configured to pick up an image of the workpiece on the pallet from an oblique upper direction. The bending system according to the present embodiment includes a first illumination unit erected on a left front side of the predetermined setting area and configured to irradiate an image pickup area of the image pickup unit with an illumination beam, and a second illumination unit erected on a right front side of the predetermined setting area and configured to irradiate the image pickup area of the image pickup unit with the illumination beam.

In a bending system according to a second embodiment, in addition to the configuration of the bending system according to the first embodiment, the first illumination unit includes a plurality of first illuminations for irradiation of illumination beams in a right obliquely downward direction, and is configured such that an irradiation direction of each of the first illuminations is adjustable so that an entire area on the pallet is irradiated with the illumination beams from the plurality of first illuminations. Further, the second illumination unit includes a plurality of second illuminations for irradiation of illumination beams in a left obliquely downward direction, and is configured such that an irradiation direction of each of the second illuminations is adjustable so that the entire area on the pallet is irradiated with the illumination beams from the plurality of second illuminations.

According to the configurations of the bending system according to the first embodiment and the second embodiment, as described above, since the image pickup unit is located above and anterior to the predetermined setting area, the image pickup unit can be sufficiently separated from the predetermined setting area. Since the first illumination unit is located on the left front side of the predetermined setting area and the second illumination unit is located on the right front side of the predetermined setting area, the first illumination unit and the second illumination unit can be sufficiently separated from the predetermined setting area. Therefore, the workpiece held by the part of the bending robot or the robot hand does not interfere with the image pickup unit, the first illumination unit, or the second illumination unit. Therefore, the operating range of the bending robot is not limited by the image pickup unit and the like.

A method for using a bending system according to a third embodiment is a method for using the bending system according to the second embodiment. Then, in a state in which an entire area on the pallet is covered with an adjustment sheet, the irradiation direction of each of the first illuminations is adjusted such that a position on the adjustment sheet is irradiated with a visible beam from a laser pointer of an adjustment jig mounted to each of the first illuminations, the position on the adjustment sheet corresponding to an irradiation range of a respective one of the first illuminations. Further, an irradiation direction of each of the second illuminations is adjusted such that a position on the adjustment sheet is irradiated with the visible beam from the laser pointer of the adjustment jig mounted to each of the second illuminations, the position on the adjustment sheet corresponding to an irradiation range of a respective one of the second illuminations.

A method for using a bending system according to a fourth embodiment is a method for using the bending system according to the second embodiment. Then, when the image pickup unit picks up an image of the workpiece on the pallet from the oblique upper direction, an illumination operation of the first illumination unit is executed so that the entire area on the pallet is irradiated with the illumination beams from the plurality of first illuminations. Further, an illumination operation of the second illumination unit is executed so that the entire area on the pallet is irradiated with the illumination beams from the plurality of second illuminations.

According to the bending system and the method for using the same described above, it is possible to increase the degree of freedom of the bending of the bending system while sufficiently ensuring the processing accuracy of the bending.

Hereinafter, a first embodiment and a second embodiment will be described with reference to <FIG>.

Note that in the description and the scope of claims of the present application, "provided" is meant to include not only directly provided but also indirectly provided via another member. "Erected" means being set up in an upright state. The "lateral direction" is one of the horizontal directions and is synonymous with a direction parallel to the width direction of the press brake. The "front-back direction" is a horizontal direction orthogonal to the lateral direction, and is synonymous with a direction parallel to the depth direction of the press brake. "Holding" is meant to include sucking and gripping. In the drawings, "FF" indicates a forward direction, "FR" indicates a backward direction, "L" indicates a left direction, "R" indicates a right direction, "U" indicates an upper direction, and "D" indicates a downward direction.

As shown in <FIG>, a bending system <NUM> according to the first embodiment is a processing system that automatically bends a plate-shaped workpiece (sheet metal) W. The bending system <NUM> includes a press brake <NUM> that bends the workpiece W through cooperation between a punch tool (not shown) and a die tool (not shown).

A predetermined setting area (carrying-in area) SA for a pallet <NUM> to be set is formed in front of the press brake <NUM>. The pallet <NUM> supports the workpiece W. In other words, in front of the press brake <NUM>, the carrying-in area SA for carrying in the workpiece W into the bending system <NUM> via the pallet <NUM> is formed. The pallet <NUM> is set in the predetermined setting area SA by a fork lifter (not shown) or a hand lifter (not shown). Note that on the right side of the predetermined setting area, a carrying-out area TA for carrying out a bent product from the bending system <NUM> via a product pallet (not shown) is formed.

As shown in <FIG> and <FIG>, a plurality of pedestals <NUM> that support the pallet <NUM> are provided on a floor surface of the predetermined setting area SA via a plurality of low head bolts <NUM> and a plurality of anchors (not shown). A plurality of half-split shims (not shown) for adjusting a height location of each of the pedestals <NUM> are interposed between each of the pedestals <NUM> and the floor surface. Therefore, by adjusting the height location of each of the pedestals <NUM>, it is possible to sufficiently ensure flatness of an upper surface of the pallet <NUM> set in the predetermined setting area SA.

As shown in <FIG>, a guide frame <NUM> extending in the lateral direction is provided between the press brake <NUM> and the predetermined setting area SA. A bending robot <NUM>, which assists in bending the workpiece W, is provided to the guide frame <NUM> in such a manner as to be movable in the lateral direction. In other words, the bending robot <NUM> is provided between the press brake <NUM> and the predetermined setting area SA in such a manner as to be movable via the guide frame <NUM> in the lateral direction. The bending robot <NUM> has a known configuration shown in Patent Literature <NUM>, for example, and includes an articulated robot arm <NUM>. The bending robot <NUM> includes a robot hand <NUM> that is provided at the distal end of the robot arm <NUM> in an installable and removeable manner. The robot hand <NUM> sucks the workpiece W on the pallet <NUM> set in the predetermined setting area SA. Note that as shown in Patent Literatures <NUM> and <NUM>, the robot hand <NUM> may include a gripper (not shown) that grips the end portion of the workpiece W.

An L-shaped support column <NUM> is erected on the floor surface on a left front side of the predetermined setting area SA, and the support column <NUM> includes a vertical portion (a perpendicular portion) 28a and a horizontal portion 28b that is provided above the vertical portion 28a. At the distal end of the horizontal portion 28b of the support column <NUM>, a monocular camera <NUM> is provided as an image pickup unit that picks up, from an oblique upper direction, an image of the workpiece W on the pallet <NUM> set in the predetermined setting area SA. In other words, the camera <NUM> is provided above and anterior to the predetermined setting area SA via the support column <NUM>. The camera <NUM> includes a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) as an image pickup element. Note that a stereo camera (not shown) may be used in lieu of the monocular camera <NUM>.

As shown in <FIG>, a first illumination stand <NUM>, as a first illumination unit that irradiates an image pickup area of the camera <NUM> with an illumination beam, is erected on the left front side of the predetermined setting area SA. The first illumination stand <NUM> is arranged to be inclined with respect to the lateral direction so that a right end side thereof is located more forward than a left end side thereof. Then, the specific contents of the respective constituent members of the first illumination stand <NUM> are as follows.

As shown in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, a first support frame <NUM> is erected on the left front side of the predetermined setting area SA. The first support frame <NUM> includes a plurality of (three in the present embodiment) first beam members <NUM> that extend in the horizontal direction. Each of the first beam members <NUM> is provided with an inverted U-shaped first bracket <NUM> via a mounting bolt <NUM>. The first bracket <NUM> is rotatable around an axial center of the mounting bolt <NUM> that is a vertical axial center.

A first illumination <NUM> for irradiation of the illumination beam in a right obliquely downward direction is provided to each of the first brackets <NUM> via a mounting bolt <NUM>. In other words, the first illumination stand <NUM> includes a plurality of (<NUM> in the present embodiment) first illuminations <NUM>. The illumination beams from the plurality of first illuminations <NUM> cast shadows on the right and rear edge portions (contour portions) of the workpiece W on the pallet <NUM> set in the predetermined setting area SA to clarify those edge portions.

As shown in <FIG>, each of the first illuminations <NUM> is rotatable around the axial center of the mounting bolt <NUM> that is a horizontal axial center. Each of the first illuminations <NUM> is rotatable around the axial center of the mounting bolt <NUM> integrally with the first bracket <NUM>. A circular arc slit <NUM> is formed on each side surface of each of the first brackets <NUM>. A movable bolt <NUM> as a movable element is provided on each side surface of each of the first illuminations <NUM>, and each of the movable bolts <NUM> moves in a state of being guided to the slit <NUM> of each of the first brackets <NUM>. Further, each of the first illuminations <NUM> includes a rectangular box-shaped illumination main body <NUM> provided to each of the first brackets <NUM> and whose front side (irradiation side) is open, an acrylic panel <NUM> provided on the front side of the illumination main body <NUM>, and a plurality of light emitting diodes (LEDs) <NUM> provided in the illumination main body <NUM>.

As described above, each of the first illuminations <NUM> is configured to be rotatable around the two orthogonal axial centers. In other words, the irradiation direction of each of the first illuminations <NUM> is configured to be adjustable so that an entire area on the pallet <NUM> is irradiated with the illumination beams from the plurality of first illuminations <NUM> (see <FIG>). The two orthogonal axial centers refer to a horizontal axial center and a vertical axial center. In <FIG>, each of the first illuminations <NUM> is attached with a numerical subscript for identification (<NUM><NUM> to <NUM><NUM>). An irradiation range C of each of the first illuminations <NUM> is attached with a numerical subscript for identification (C<NUM> to C<NUM>). Further, when the irradiation direction of each of the first illuminations <NUM> is adjusted, an adjustment jig <NUM> is used. The adjustment jig <NUM> includes a jig main body <NUM> that can be magnetically attached to an appropriate location of each of the illumination main bodies <NUM>, and a laser pointer <NUM> that is provided to the jig main body <NUM> and emits a visible beam.

As shown in <FIG>, a second illumination stand <NUM>, as a second illumination unit that irradiates the image pickup area of the camera <NUM> with the illumination beam, is erected on the right front side of the predetermined setting area SA. The second illumination stand <NUM> is arranged to be inclined with respect to the lateral direction so that a left end side thereof is located more forward than a right end side thereof. The second illumination stand <NUM> is separated from the first illumination stand <NUM> in the lateral direction, and a taking-in and out passage EG for taking in and out the pallet <NUM> with respect to the predetermined setting area SA is formed between the first illumination stand <NUM> and the second illumination stand <NUM>. Then, the specific contents of the respective constituent members of the second illumination stand <NUM> are as follows.

As shown in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, a second support frame <NUM> is erected on the right front side of the predetermined setting area SA. The second support frame <NUM> includes a plurality of (three in the present embodiment) second beam members <NUM> that extend in the horizontal direction. Each of the second beam members <NUM> is provided with an inverted U-shaped second bracket <NUM> via a mounting bolt <NUM>. The second bracket <NUM> is rotatable around the axial center of the mounting bolt <NUM> that is a vertical axial center.

A second illumination <NUM> for irradiation of the illumination beam in a left obliquely downward direction is provided to each of the second brackets <NUM> via a mounting bolt <NUM>. In other words, the second illumination stand <NUM> includes a plurality of (<NUM> in the present embodiment) second illuminations <NUM>. The plurality of second illuminations <NUM> cast shadows on the left and rear edge portions (contour portions) of the workpiece W on the pallet <NUM> set in the predetermined setting area SA to clarify those edge portions.

As shown in <FIG>, <FIG>, and <FIG>, each of the second illuminations <NUM> is rotatable around the axial center of the mounting bolt <NUM> that is a horizontal axial center. Each of the second illuminations <NUM> is rotatable around the axial center of the mounting bolt <NUM> integrally with the second bracket <NUM>. A circular arc slit <NUM> is formed on each side surface of each of the second brackets <NUM>. A movable bolt <NUM> as a movable element is provided on each side surface of each of the second illuminations <NUM>, and each of the movable bolts <NUM> moves in a state of being guided to the slit <NUM> of each of the second brackets <NUM>. Further, each of the second illuminations <NUM> includes a rectangular box-shaped illumination main body <NUM> provided to each of the second brackets <NUM> and whose front side (irradiation side) is open, an acrylic panel <NUM> provided on the front side of the illumination main body <NUM>, and a plurality of light emitting diodes (LEDs) <NUM> provided in the illumination main body <NUM>.

As described above, each of the second illuminations <NUM> is configured to be rotatable around the two orthogonal axial centers. In other words, the irradiation direction of each of the second illuminations <NUM> is configured to be adjustable so that the entire area on the pallet <NUM> set in the predetermined setting area SA is irradiated with the illumination beams from the plurality of second illuminations <NUM> (See <FIG>). In <FIG>, each of the second illuminations <NUM> is attached with a numerical subscript for identification (<NUM><NUM> to <NUM><NUM>). The irradiation range C of each of the second illuminations <NUM> is attached with a numerical subscript for identification (C<NUM> to C<NUM>). Further, when the irradiation direction of each of the second illuminations <NUM> is adjusted, the adjustment jig <NUM> is used as described above. The jig main body <NUM> of the adjustment jig <NUM> can be magnetically attached to an appropriate location of each of the illumination main bodies <NUM>.

As shown in <FIG>, a first guard <NUM> that protects the first illumination stand <NUM> is provided in the vicinity of the right side of the first illumination stand <NUM>. The first guard <NUM> is arranged to be along the first illumination stand <NUM>. A second guard <NUM> that protects the second illumination stand <NUM> is provided in the vicinity of the left side of the second illumination stand <NUM>. The second guard <NUM> is arranged to be along the second illumination stand <NUM>. Further, a safety fence <NUM> for ensuring the safety of the bending is provided around most of the bending system <NUM>. The safety fence <NUM> includes a plurality of doors (not shown) for allowing the fork lifter or the hand lifter to pass through.

Although not shown, the bending system <NUM> includes a numerical control device (a main control device) that controls the press brake <NUM>, and a robot control device that controls the bending robot <NUM>. The bending system <NUM> includes an illumination control device that controls the first illumination stand <NUM> and the second illumination stand <NUM>, and an image processing device that performs image processing to a picked-up image of the camera <NUM>. The illumination control device separately executes an irradiation operation of the illumination beams from the plurality of first illuminations <NUM> and an irradiation operation of the illumination beams from the plurality of second illuminations <NUM>. The image processing device corrects a distortion of the picked-up image of the camera <NUM>, which is caused by the inclination of the image pickup direction of the camera <NUM> with respect to the vertical direction. The image processing device detects the location of the workpiece W on the pallet <NUM> based on the corrected picked-up image of the camera <NUM>. The robot control device controls the bending robot <NUM> so that the robot hand <NUM> holds a predetermined portion of the workpiece W based on the detected location of the workpiece W. Therefore, even if the workpiece W is not placed accurately at a predetermined position on the pallet <NUM>, it is possible to sufficiently ensure the processing accuracy of the bending by appropriately operating the bending robot <NUM>.

Next, a method for using the bending system according to the first embodiment will be described.

As shown in <FIG> and <FIG>, in a state in which the entire area of the pallet <NUM> is covered with a white adjustment sheet FS, the irradiation direction of each of the first illuminations <NUM> is adjusted such that a position P on the adjustment sheet FS, which corresponds to the irradiation range C of each of the first illuminations <NUM>, is irradiated with the visible beam from the laser pointer <NUM> (see <FIG>) of the adjustment jig <NUM> mounted to each of the first illuminations <NUM>. Thereby, the illumination beams of the first illumination stand <NUM> can be adjusted. In <FIG>, each of the first illuminations <NUM> is attached with a numerical subscript for identification (<NUM><NUM> to <NUM><NUM>). The position P corresponding to the irradiation range C (C<NUM> to C<NUM>) of each of the first illuminations <NUM> (<NUM><NUM> to <NUM><NUM>) is attached with a numerical subscript for identification (P<NUM> to P<NUM>).

Further, as shown in <FIG> and <FIG>, in the state in which the entire area on the pallet <NUM> is covered with the adjustment sheet FS, the irradiation direction of each of the second illuminations <NUM> is adjusted such that the position P on the adjustment sheet FS, which corresponds to the irradiation range C of each of the second illuminations <NUM>, is irradiated with the visible beam from the laser pointer <NUM> (see <FIG>) of the adjustment jig <NUM> mounted to each of the second illuminations <NUM>. Thereby, the illumination beams of the second illumination stand <NUM> can be adjusted. In <FIG>, each of the second illuminations <NUM> is attached with a numerical subscript for identification (<NUM><NUM> to <NUM><NUM>). The position P corresponding to the irradiation range C (C<NUM> to C<NUM>) of each of the second illuminations <NUM> (<NUM><NUM> to <NUM><NUM>) is attached with a numerical subscript for identification (P<NUM> to P<NUM>).

As shown in <FIG>, when the camera <NUM> picks up an image of the workpiece W on the pallet <NUM> from the oblique upper direction, an illumination operation of the first illumination stand <NUM> is executed so that the entire area on the pallet <NUM> is irradiated with the illumination beams from the plurality of first illuminations <NUM>. Then, shadows can be casted on the right and rear edge portions of the workpiece W on the pallet <NUM> to clarify those edge portions. Since the illumination beams from the plurality of first illuminations <NUM> are directed in the right obliquely downward direction, the end surfaces of the left and front edge portions of the workpiece W on the pallet <NUM> can be recognized by the camera <NUM>. Therefore, it is not necessary to cast shadows on those edge portions. Further, an illumination operation of the second illumination stand <NUM> is executed so that the entire area on the pallet <NUM> is irradiated with the illumination beams from the plurality of second illuminations <NUM>. Then, shadows can be casted on the left and rear edge portions of the workpiece W on the pallet <NUM> to clarify those edge portions. Since the illumination beams from the plurality of second illuminations <NUM> are directed in the left obliquely downward direction, the end surfaces of the right and front edge portions of the workpiece W on the pallet <NUM> can be recognized by the camera <NUM>. Therefore, it is not necessary to cast shadows on these edges. The execution timings of the illumination operation of the first illumination stand <NUM> and the illumination operation of the second illumination stand <NUM> are staggered. By clarifying the right, left, and rear edge portions of the workpiece W on the pallet <NUM>, the image processing device can easily detect the location of the workpiece W by pattern matching.

Next, the operation and effect of the first embodiment will be described.

As described above, since the camera <NUM> is located above and anterior to the predetermined setting area SA, the camera <NUM> can be sufficiently separated from the predetermined setting area SA. Since the first illumination stand <NUM> is located on the left front side of the predetermined setting area SA and the second illumination stand <NUM> is located on the right front side of the predetermined setting area SA, the first illumination stand <NUM> and the second illumination stand <NUM> can be sufficiently separated from the predetermined setting area SA. Therefore, the workpiece W sucked by a part of the bending robot <NUM> or the robot hand <NUM> does not interfere with the camera <NUM>, the first illumination stand <NUM>, and the second illumination stand <NUM>. In other words, the operating range of the bending robot <NUM> that sucks the workpiece W is not limited by the camera <NUM> or the like. Therefore, according to the first embodiment, it is possible to increase the degree of freedom of the bending of the bending system <NUM> while sufficiently ensuring the processing accuracy of the bending.

As described above, the first illumination stand <NUM> is arranged to be inclined with respect to the lateral direction so that the right end side thereof is located more forward than the left end side thereof. The second illumination stand <NUM> is arranged to be inclined with respect to the lateral direction so that the left end side thereof is located more forward than the right end side thereof. A taking-in and out passage EG is formed between the first illumination stand <NUM> and the second illumination stand <NUM>. Therefore, it is possible to sufficiently ensure a worker flow line in the vicinity of the predetermined setting area SA while allowing the pallet <NUM> to be taken in and out with respect to the predetermined setting area SA. Therefore, according to the first embodiment, the workability and operability of the bending system <NUM> can be improved.

As described above, the first guard <NUM> is provided in the vicinity of the right side of the first illumination stand <NUM>, and the second guard <NUM> is provided in the vicinity of the left side of the second illumination stand <NUM>. Therefore, according to the first embodiment, damage to the first illumination stand <NUM> or the second illumination stand <NUM> due to contact with the fork lifter or the hand lifter can be sufficiently prevented.

As shown in <FIG>, a bending system <NUM> according to a second embodiment automatically bends the workpiece W in the same manner as the bending system <NUM> of the first embodiment (see <FIG>). The bending system <NUM> has the same configurations as the bending system <NUM> except for a part, and of the configurations of the bending system <NUM>, a configuration and the like different from those of the bending system <NUM> will be described. Note that of a plurality of constituent members of the bending system <NUM>, those corresponding to the constituent members of the bending system <NUM> are denoted by the same reference numerals in the drawings.

The first illumination stand <NUM> that irradiates the image pickup area of the camera <NUM> with the illumination beam is erected on the left front side of the predetermined setting area SA. The first illumination stand <NUM> is arranged in parallel along the lateral direction. A second illumination stand <NUM> that irradiates the image pickup area of the camera <NUM> with the illumination beam is erected on the right front side of the predetermined setting area SA. The second illumination stand <NUM> is arranged in parallel along the lateral direction. Note that the first illumination stand <NUM> and the second illumination stand <NUM> may each has a caster attached with a brake (not shown). A first guard (not shown) that protects the first illumination stand <NUM> may be provided in the vicinity of the first illumination stand <NUM>. A second guard (not shown) that protects the second illumination stand <NUM> may be provided in the vicinity of the second illumination stand <NUM>.

Next, the operation and effect of the second embodiment will be described.

Claim 1:
A bending system (<NUM>, <NUM>), comprising:
a bending robot (<NUM>) provided between a press brake (<NUM>) and a predetermined setting area (SA) arranged in front of the press brake (<NUM>), including a robot hand (<NUM>) for holding a workpiece (W) on a pallet (<NUM>) set in the predetermined setting area (SA), and configured to assist in bending the workpiece (W);
a first illumination unit (<NUM>) erected on a left front side of the predetermined setting area (SA) and configured to irradiate an image pickup area of an image pickup unit (<NUM>) with an illumination beam; and
a second illumination unit (<NUM>) erected on a right front side of the predetermined setting area (SA) and configured to irradiate the image pickup area of the image pickup unit (<NUM>) with an illumination beam,
characterized by the image pickup unit (<NUM>) provided above and in front of the predetermined setting area (SA) and configured to pick up an image of the workpiece (W) on the pallet (<NUM>) from an oblique upper direction.