JP2017192974A - Bending machine and bending method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply accurate bending processing to a workpiece W by maintaining the positioning accuracy of the workpiece W in a fore-and-aft direction even if a thickness of the workpiece W is thin.SOLUTION: An abutment member 49 moves to a fore-and-aft direction by the drive of a fore-and-aft moving servo motor 33. The abutment member 49 has an abutment main body 51 which is arranged at an upper side of a second slider 45, and a pressure sensor 55 which is arranged at a front surface side of the abutment main body 51 via an elastic body 53, and detects pressure which acts on the abutment member 49 side. A press brake 1 comprises a pressure distribution analysis part 61 for analyzing a pressure distribution D acting on the abutment member 49 side on the basis of a detection result from a pressure sensor sheet 55, a determination part 63 for determining whether or not the pressure distribution D conforms to an abutment pattern P corresponding to workpiece information, and a permission signal output part 65 for outputting a prescribed permission signal when it is determined that the pressure distribution D and the abutment pattern P conform to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bending machine such as a press brake for bending a workpiece by cooperation of an upper die and a lower die.

  Generally, a bending machine includes a main body frame and a lower table that is provided at a lower portion of the main body frame and holds a lower mold on the upper side. Further, the bending machine includes an upper table that is provided at the upper part of the main body frame so as to be movable up and down and that holds the upper mold on the lower side, and a hydraulic cylinder for raising and lowering the upper table.

  The bending machine includes a back gauge provided on the back side (rear) of the lower table and for positioning the workpiece in the depth direction (front-rear direction) with respect to the lower mold. The back gauge has an abutting member capable of abutting the end face of the workpiece, and the abutting member is movable in the depth direction. Further, the abutting member has a plurality of abutting detection portions that detect that the end surface of the workpiece has abutted against the front surface (abutting surface) of the abutting member. It is arranged at intervals along the direction. Each contact detection unit includes a contact piece that contacts the end surface of the workpiece prior to the front surface of the abutting member, and a limit switch (micro switch) that detects that the contact piece is displaced by contact with the end surface of the workpiece. (See Patent Document 1).

JP 2006-130554 A

  By the way, in order to accurately position the work in the depth direction (predetermined position in the depth direction) with respect to the lower mold, the pressing force of the work on the abutting member side by the operator is increased to some extent, While displacing, it is necessary to bring the end face of the workpiece into contact with the front surface of the abutting member. On the other hand, if the workpiece is thin and the workpiece has low rigidity, the workpiece may be warped when the end surface of the workpiece is abutted against the front surface of the abutting member. In such a case, there is a problem in that the positioning accuracy in the depth direction of the workpiece is lowered, leading to processing defects.

  Accordingly, an object of the present invention is to provide a bending machine or the like having a novel configuration that can solve the above-described problems.

  According to a first aspect of the present invention, a lower table is provided at a lower portion of a main body frame and holds a lower mold on an upper side, and the upper portion of the main body frame can be moved up and down relative to the lower table (in a vertical direction) An upper table that holds the upper mold on the lower side, an actuator for raising and lowering the upper table relative to the lower table, and a rear side (rear side) of the lower table And a back gauge for positioning the workpiece in the depth direction with respect to the lower mold, and an abutting member that is movable in the depth direction (front-rear direction) and capable of abutting the end surface of the workpiece. The abutting member has a pressure sensor sheet for detecting pressure (surface pressure) acting on the abutting member side on the front side thereof.

  According to the first aspect of the present invention, the end surface of the workpiece is abutted against the pressure sensor sheet on the front side of the abutting member positioned in the depth direction (predetermined position in the depth direction). Then, when it is determined that the positioning of the workpiece in the depth direction is appropriate based on the detection result from the pressure sensor sheet, the upper table is moved relative to the lower table by driving the lifting actuator. To lower. Thereby, a bending process can be performed with respect to a workpiece | work by cooperation of the said upper mold and the said lower mold.

  As described above, the abutting member has the pressure sensor sheet on the front side thereof. Therefore, even if the pressing force of the work on the abutting member side by the operator is small, the pressure that the pressure sensor sheet acts on the abutting member side can be accurately detected. Then, it is possible to determine whether or not the positioning of the workpiece in the depth direction is appropriate based on the detection result from the pressure sensor sheet. That is, positioning of the workpiece in the depth direction can be performed appropriately even if the pressing force of the workpiece on the abutting member side is small.

  A second aspect of the present invention is a bending process comprising: a lower table provided at a lower portion of a main body frame; and an upper table provided at an upper portion of the main body frame so as to be movable up and down relative to the lower table. A bending method (bending process) for bending a workpiece by cooperation of an upper mold held on the lower side of the upper table and a lower mold held on the upper side of the lower table. The pressure sensor sheet in a state in which the end surface of the workpiece is abutted against the pressure sensor sheet provided on the front side of the abutting member positioned in the depth direction (predetermined position in the depth direction). Pressure distribution analysis step for analyzing the pressure distribution (pressure distribution pattern) acting on the abutting member side based on the detection result from the pressure, the pressure distribution and the work information (information on the work) A determination step for determining whether or not the abutting pattern according to the condition is matched, and when it is determined that the pressure distribution and the abutting pattern are matched, a relative lowering operation of the upper table is performed. And a permission signal output step of outputting a permission signal for permission.

  According to the second aspect of the present invention, as described above, the abutting member has the pressure sensor sheet on the front side thereof. Therefore, even if the pressing force of the work on the abutting member side by the operator is small, the pressure acting on the abutting member side can be accurately detected by the pressure sensor sheet. Then, the pressure distribution is analyzed based on the detection result from the pressure sensor sheet, and it can be determined whether or not the pressure distribution and the abutting pattern are matched. In other words, it is possible to determine whether or not the positioning of the workpiece in the depth direction is appropriate based on the detection result from the pressure sensor sheet. That is, positioning of the workpiece in the depth direction can be performed appropriately even if the pressing force of the workpiece on the abutting member side is small.

  According to the present invention, even when the workpiece is thin and the workpiece has low rigidity, it is possible to sufficiently suppress the workpiece from warping when the end surface of the workpiece is abutted against the front surface of the abutting member. . Therefore, according to the present invention, even if the workpiece is thin and the workpiece rigidity is small, the workpiece can be bent with high accuracy while maintaining the positioning accuracy in the depth direction of the workpiece.

FIG. 1 is a schematic perspective view of a press brake according to an embodiment of the present invention. FIG. 2 is a schematic partial side sectional view of a press brake according to an embodiment of the present invention. It is a typical perspective view which shows a mode that the end surface of a workpiece | work is abutted against the pressure sensor sheet | seat of the front side of an abutting member. FIG. 4 is a control block diagram of the press brake according to the embodiment of the present invention. Fig.5 (a) is a perspective view which shows the workpiece | work of a thin small thing (narrow), FIG.5 (b) is a figure which shows one linear pattern as an abutment pattern. FIG. 6A is a perspective view showing a wide workpiece having a small thickness, and FIG. 6B is a diagram showing two linear patterns as abutting patterns. FIG. 7A is a perspective view showing a small workpiece having an end face formed in a comb-teeth shape, and FIG. 7B is a diagram showing one intermittent pattern as an abutment pattern. FIG. 8A is a perspective view showing a small work having an end face formed in a flange shape, and FIG. 8B is a view showing one rectangular pattern as an abutment pattern. FIG. 9A shows a state in which the width of one pressure distribution (pressure distribution pattern) is the same as the width of one linear pattern, and FIG. 9B shows that the width of one pressure distribution is 1. It is a figure which shows a mode different from the width | variety of two linear patterns. FIG. 10A is a diagram illustrating a state in which two pressure distributions have the same width as two linear patterns, and FIG. 10B illustrates that two pressure distributions have two linear patterns in width. It is a figure which shows a different mode. FIG. 11A is a diagram illustrating a state in which the width of one pressure distribution is the same as the width of one intermittent pattern, and FIG. 11B illustrates the width of one pressure distribution as the width of one intermittent pattern. It is a figure which shows a different mode. FIG. 12A is a diagram showing a state in which the width of one pressure distribution is the same as the width of one rectangular pattern, and FIG. 12B shows the width of one rectangular distribution as the width of one rectangular pattern. It is a figure which shows a different mode. FIG. 13 is a flowchart for explaining a bending method (press brake control method) according to an embodiment of the present invention.

  Embodiments of the present invention will be sequentially described with reference to FIGS. 1 to 13.

  In the specification and claims of the present application, “provided” means not only being provided directly but also indirectly provided via another member. Is synonymous with. “Providing” means to provide indirectly through another member in addition to providing directly, and is synonymous with “providing”. The “width direction” means the width direction of a bending machine such as a press brake, and is synonymous with the left-right direction. The “depth direction” means the depth direction of a bending machine such as a press brake, and is synonymous with the front-rear direction. In the drawing, “FF” is the forward direction, “FR” is the backward direction, “L” is the left direction, “R” is the right direction, “U” is the upward direction, and “D” is the downward direction. Respectively.

  As shown in FIGS. 1 to 3, the press brake 1 according to the embodiment of the present invention performs a bending process on a plate-shaped workpiece (sheet metal) W by cooperation of an upper mold 3 and a lower mold 5. One of the bending machines. The press brake 1 includes a main body frame 7, and the main body frame 7 includes a pair of side plates 9 that are spaced apart from each other in the left-right direction and a plurality of connection bars that connect the pair of side plates 9 (not shown). And have.

  The main body frame 7 includes a lower table 11 extending in the left-right direction at the lower portion thereof. The lower table 11 detachably holds the lower mold 5 via the lower mold holder 13 on the upper side thereof. The main body frame 7 includes an upper table 15 extending in the left-right direction at an upper portion thereof so as to be movable up and down (movable in the vertical direction). The upper table 15 faces the lower table 11 in the vertical direction. The upper table 15 detachably holds the upper mold 3 via an upper mold holder 17 on the lower side thereof. The pair of side plates 9 are respectively provided with an elevation hydraulic cylinder 19 as an elevation actuator for raising and lowering the upper table 15 at the upper part thereof.

  Instead of configuring the upper table 15 to be movable up and down, the lower table 11 may be configured to be movable up and down. A servo motor (not shown) may be used instead of the lifting hydraulic cylinder 19 as the lifting actuator.

  One side plate 9 includes a linear scale 21 at an appropriate position as an example of a height detector that detects the height position of the upper table 15, in other words, the height position of the tip of the upper mold 3. ing. The press brake 1 includes a foot switch 23 that is disposed on the front side of the lower table 11 and serves as a start switch that outputs a predetermined start signal. The predetermined activation signal is a signal for starting the lowering operation of the upper table 15 by driving the pair of lifting hydraulic cylinders 19.

  The main body frame 7 includes a back gauge 25 on the back side (rear side) of the lower table 11 for positioning the work W with respect to the lower mold 5 in the front-rear direction. The specific configuration of the back gauge 25 is as follows.

  The main body frame 7 includes a pair of support members 27 (only one is shown) extending in the front-rear direction on the back side of the lower table 11, and the pair of support members 27 are separated in the left-right direction. Each support member 27 has a guide rail 29 extending in the front-rear direction on the side thereof. Each support member 27 is provided on a guide rail 29 so that the first slider 31 can be moved in the front-rear direction. Each support member 27 includes a forward / backward movement servomotor 33 for moving the first slider 31 in the front / rear direction at an appropriate position.

  Each first slider 31 has a pair of elevating guides 35 on the front side thereof, and the pair of elevating guides 35 are spaced apart in the vertical direction. Each first slider 31 includes an elevating body 37 (only one is shown) between a pair of elevating guides 35 so as to be elevable. Each lifting / lowering body 37 includes a lifting / lowering servomotor 39 for lifting / lowering the lifting / lowering body 37 at an appropriate position.

  A pair of raising / lowering bodies 37 are provided so that the stretch 41 extended in the left-right direction may be bridged between them. The stretch 41 has a pair of guide rails 43 extending in the left-right direction at appropriate positions. The stretch 41 includes a second slider 45 that can move in the left-right direction between the pair of guide rails 43. Each second slider 45 includes a left-right movement servo motor 47 for moving the second slider 45 in the left-right direction at an appropriate position.

  Each second slider 45 includes an abutting member 49 that can abut the end surface of the workpiece W on the upper side thereof. In other words, each abutting member 49 is provided on the back side of the lower table 11 in the main body frame 7 via a pair of support members 27 and the like. Each abutting member 49 can move in the front-rear direction integrally with the first slider 31, can move up and down integrally with the elevating body 37, and can move in the left-right direction integrally with the second slider 45. . In other words, each abutting member 49 moves in the front-rear direction by driving the front-rear servo motor 33, moves up and down by driving the elevating servo motor 39, and moves left-right by driving the left-right movement servo motor 47. It is supposed to move.

  Each abutting member 49 includes an abutting body 51 provided on the upper side of the second slider 45 and an elastic body (elastic sheet) 53 provided on the front side (front side) of the abutting body 51. . Each abutting member 49 has a pressure sensor sheet 55 that is provided on the front side of the elastic body 53 and detects pressure (surface pressure) acting on the abutting member 49 side (abutting main body 51 side). When the pressure sensor sheet 55 has sufficient elastic force, the elastic body 53 may be omitted from the configuration of each abutting member 49.

  As shown in FIG. 4, the press brake 1 includes a control device 57 configured by one or a plurality of computers. The control device 57 controls the lifting hydraulic cylinder 19, the back-and-forth moving servo motor 33, the lifting servo motor 39, the left-right moving servo motor 47, and the like based on a bending program. In addition, the control device 57 includes a bending process program, mold information (information on the upper mold 3 and the lower mold 5), work information (information indicating the material of the work W, the shape of the end face side of the work W, etc.), product It has a memory (not shown) for storing information (information representing product shape and the like) and the like, and a CPU (not shown) for interpreting and executing a bending program. Further, the linear scale 21, the foot switch 23, the pair of pressure sensor sheets 55, and the like are connected to the control device 57.

  The CPU of the control device 57 has a function as the pattern setting unit 59, a function as the pressure distribution analysis unit 61, a function as the determination unit 63, a function as the permission signal output unit 65, and a function as the stop signal output unit 67. Have. The control device 57 is connected to a display 69 that displays mold information, work information, product information, and the like, and the display 69 has a function as a notification unit. The contents of each function in the control device 57 are as follows.

  The pattern setting unit 59 sets an abutment pattern P (see FIG. 5B and the like) based on work information (including work end face information indicating the shape of the end face side of the work W). The abutting pattern P refers to the shape (abutting shape) of the end face of the workpiece W that is assumed to abut against the pressure sensor sheet 55. When the workpiece W is a small object (narrow) and the end surface of the workpiece W hits one pressure sensor sheet 55, the pattern setting unit 59 sets one abutting pattern P. When the workpiece W is wide and the end surface of the workpiece W abuts against the two pressure sensor sheets 55, the pattern setting unit 59 sets two abutting patterns P.

  Specifically, as shown in FIGS. 5A and 5B, the pattern setting unit 59 has a case where the workpiece W is thin (for example, 1.0 mm or less) and the workpiece W is small (narrow). In this case, one linear pattern (linear shape) SP is set as the abutting pattern P. As shown in FIGS. 6B and 6B, the pattern setting unit 59 sets two linear patterns SP as the butting pattern P when the workpiece W is thin and the workpiece W is wide. To do.

  As shown in FIGS. 7A and 7B, the pattern setting unit 59 has an intermittent pattern (intermittent pattern) as the abutment pattern P when the end surface side of the work W is formed in a comb-tooth shape and the work W is small. Shape) Set RP. As shown in FIGS. 8A and 8B, the pattern setting unit 59 sets one rectangular pattern RP as the abutting pattern P when the end surface side of the workpiece W is formed in a flange shape and is a small object. . The abutting pattern (abutting shape) P set by the pattern setting unit 59 is stored in the memory of the control device 57 as the abutting pattern P corresponding to the work information.

  As shown in FIG. 4, the pressure distribution analysis unit 61 performs pressure distribution (pressure distribution pattern) D (see FIG. 9, etc.) acting on the abutting member 49 side based on the detection result (detection value) from the pressure sensor sheet 55. ). When the workpiece W is a small object and the end surface of the workpiece W hits one pressure sensor sheet 55, the pressure distribution analysis unit 61 analyzes the pressure distribution D based on the detection result from the one pressure sensor sheet 55. To do. When the workpiece W is wide and the end surfaces of the workpiece W abut against the two pressure sensor sheets 55, the pressure distribution analysis unit 61 determines the pressure distribution D based on the detection results from the two pressure sensor sheets 55, respectively. To analyze. Note that the pressure distribution analysis unit 61 excludes pressures (detected values) that are less than a predetermined threshold set in advance from the analysis determination targets.

  Whether the determination unit 63 matches the abutting pattern P (see FIG. 5B, etc.) according to the analyzed pressure distribution and the workpiece information (including workpiece end surface information indicating the shape of the end surface side of the workpiece W). It is to determine whether or not. Whether or not the pressure distribution (pressure distribution pattern) D and the abutting pattern P are compatible is the same as the width of the pressure distribution D (length in the left-right direction) and the width of the abutting pattern P (length in the left-right direction). It is decided whether or not.

  Specifically, as shown in FIGS. 5A, 5 </ b> B, and 9 </ b> A, the determination unit 63 uses one pressure distribution D when the workpiece W is thin and the workpiece W is a small object. If the width (k) of one and the width (j) of one linear pattern SP are the same, it is determined that the abutting pattern P corresponding to the pressure distribution D and the workpiece information is matched. As shown in FIGS. 5B and 9B, the determination unit 63 determines that the width (k) of one pressure distribution D and the width (j) of one linear pattern SP are different (FIG. 5B). ) And FIG. 7B), it is determined that the pressure distribution D and the abutting pattern P corresponding to the workpiece information do not match.

  As shown in FIGS. 6A, 6 </ b> B, and 10 </ b> A, the determination unit 63 determines the width (k1 + k2) of the two pressure distributions D when the workpiece W is thin and the workpiece W is wide. If the widths (j1 + j2) of the two linear patterns SP are the same, it is determined that the pressure distribution D and the abutting pattern P corresponding to the workpiece information match. As shown in FIGS. 6B and 10B, the determination unit 63 determines that the pressure distribution D and the width (k1 + k2) of the two pressure distributions D are different from the width (j1 + j2) of the two linear patterns SP. It determines with the abutting pattern P according to workpiece | work information not matching.

  Similarly, as shown in FIGS. 7A, 7 </ b> B, and 11 </ b> A, the determination unit 63 has one piece when the end face side of the work W is formed in a comb-tooth shape and the work W is a small object. If the width k of the pressure distribution D and the width j of one intermittent pattern IP are the same, it is determined that the abutting pattern P corresponding to the pressure distribution D and the workpiece information is matched. As shown in FIGS. 7B and 11B, when the width k of one pressure distribution D and the width j of one intermittent pattern IP are different, the determination unit 63 responds to the pressure distribution D and the work information. It is determined that the abutting pattern P is not suitable.

  As shown in FIGS. 8A, 8 </ b> B, and 12 </ b> A, the determination unit 63 determines the width (k) of one pressure distribution D when the end surface side of the workpiece W is formed in a flange shape and is a small object. ) And the width (j) of one rectangular pattern RP are the same, it is determined that the pressure distribution D and the abutting pattern P corresponding to the workpiece information are matched. As shown in FIGS. 8B and 12B, the determination unit 63 determines that the pressure distribution D and the width (k) of one pressure distribution D are different from the width (j) of one rectangular pattern RP. It determines with the abutting pattern P according to workpiece | work information not matching.

  As shown in FIG. 4, the permission signal output unit 65 determines that the pressure distribution and the abutting pattern are matched on condition that a predetermined activation signal is input from the foot switch 23. A predetermined permission signal is output. The predetermined permission signal is a signal for starting the lowering operation of the upper table 15 by driving the pair of lifting hydraulic cylinders 19.

  The stop signal output unit 67 starts the lowering operation of the upper table 15 until the tip of the upper mold 3 reaches the pinching point, and the pressure distribution D (see FIG. 9 and the like) and the abutting pattern P A predetermined stop signal is output when it is determined that (see FIG. 5B, etc.) is not compatible. The pinching point is a height position where the tip of the upper mold 3 is in contact with the upper surface of the workpiece W. Whether or not the tip of the upper mold 3 has reached the pinching point is determined by the CPU of the control device 57 based on the detection value (detection result) from the linear scale 21. The predetermined stop signal is a signal for stopping the driving of the pair of lifting hydraulic cylinders 19.

  The display device 69 as a notification unit notifies the determination result when it is determined that the pressure distribution D and the butting pattern P do not match. Specifically, when it is determined that the pressure distribution D and the butting pattern P do not match, the display unit 69 performs lighting display, blinking display, or message display for indicating the determination result. Instead of notifying the determination result by display on the display device 69, the determination result may be notified by sound from a sound generator (not shown).

  Subsequently, a bending method (control method of the press brake 1) according to the embodiment of the present invention will be described including the operation of the embodiment of the present invention with reference to FIG. Here, the bending method according to the embodiment of the present invention is a method for bending a plate-like workpiece W using the press brake 1 and the cooperation of the upper die 3 and the lower die 5. is there. The bending method according to the embodiment of the present invention includes a pressure distribution analysis step, a determination step, a permission signal output step, a prohibition signal output step, and a notification step.

  First, by controlling the servo motors 33 for back and forth movement by the CPU of the control device 57, the abutment members 49 are moved in the front and back directions and positioned at predetermined positions in the front and back directions according to product information and the like. Further, if necessary, the abutting member 49 is positioned at a height position corresponding to the lower mold 5 by controlling the lift servo motor 39 by the CPU of the control device 57. The left and right movement servomotors 47 are controlled by the CPU of the control device 57, so that each abutting member 49 is moved in the left-right direction and positioned at a predetermined position in the left-right direction. Thereby, the CPU of the control device 57 can prepare for the abutment of the workpiece W (step S101 in FIG. 13).

  After preparing for the abutment of the workpiece W, the end face of the workpiece W is abutted against the pressure sensor sheet 55 on the front side of one or two abutting members 49 while the worker O holds the workpiece W (see FIG. 13 step S102). Then, the pressure (surface pressure) at which one or two pressure sensor sheets 55 act on the abutting member 49 side can be detected. Then, the pressure distribution analysis unit 61 analyzes the pressure distribution (pressure distribution pattern) D acting on the abutting member 49 side based on the detection results from the one or two pressure sensor sheets 55 (step S103 in FIG. 13). Pressure distribution analysis step). The analysis of the pressure distribution D by the pressure distribution analysis unit 61 is continued until the tip of the upper mold 3 reaches the pinching point.

  The determination unit 63 determines whether or not the analyzed pressure distribution D and the abutting pattern P corresponding to the workpiece information are compatible (step S104 in FIG. 13, determination step). When it is determined that the pressure distribution D and the abutting pattern P corresponding to the workpiece information are matched (Yes in step S104 in FIG. 13), a predetermined activation signal is input from the foot switch 23. As a condition (step S105 in FIG. 13), the permission signal output unit 65 outputs a predetermined permission signal (step S106 in FIG. 13, permission signal output step). Then, the CPU of the control device 57 can start the lowering operation of the upper table 15 by driving the pair of lifting hydraulic cylinders 19 (step S107 in FIG. 13).

  From the start of the lowering operation of the upper table 15 to the time when the tip of the upper mold 3 reaches the pinching point, the determination unit 63 has an abutting pattern P corresponding to the analyzed pressure distribution D and workpiece information. It is continuously determined whether or not it conforms (step S108 in FIG. 13). When it is continuously determined that the abutting pattern P according to the pressure distribution D and the workpiece information is matched (Yes in step S108 in FIG. 13), the press brake 1 is connected to the upper mold 3. The workpiece W is bent by the cooperation (engagement) of the lower mold 5 (step S109 in FIG. 13).

  On the other hand, if it is determined in step S104 in FIG. 13 that the pressure distribution D and the abutting pattern P corresponding to the workpiece information are not compatible (No in step S104 in FIG. 13), the notification unit The display 69 notifies the determination result (step S110 in FIG. 13, notification step). Then, the process returns to step S102 in FIG. 13 and the processes after step S102 in FIG. 13 are executed by the worker O and the control device 57.

  When it is determined in step S108 in FIG. 13 that the pressure distribution D and the abutting pattern P corresponding to the work information are not matched (in the case of No in step S108 in FIG. 13), the stop signal output unit 67 outputs a predetermined stop signal (step S111 in FIG. 13, stop signal output step). Then, the CPU of the control device 57 stops driving the pair of lifting hydraulic cylinders 19 and interrupts the lowering operation of the upper table 15 (step S112 in FIG. 13). Moreover, the indicator 69 as a notification part notifies the determination result (step S113 of FIG. 13, notification step). Then, the process returns to step S102 in FIG. 13 and the processes after step S102 in FIG. 13 are executed by the worker O and the control device 57.

  As described above, each abutting member 49 has the pressure sensor sheet 55 on the front side thereof. Therefore, even if the pressing force of the work W on the abutting member 49 side by the worker O is small, the pressure acting on the abutting member 49 side can be accurately detected by one or two pressure sensor sheets 55. Then, one or two pressure distributions (pressure distribution patterns) D are analyzed based on detection results from one or two pressure sensor sheets 55, and an abutment pattern P corresponding to the pressure distribution D and the work information is obtained. It can be determined whether or not it is compatible. In other words, it is possible to determine whether or not the positioning of the workpiece W in the front-rear direction is appropriate based on the detection results from the one or two pressure sensor sheets 55. That is, even if the pressing force of the work W on the abutting member 49 side by the worker O is small, the work W can be properly positioned in the front-rear direction.

  In addition, since each abutting member 49 has a pressure sensor sheet 55 on the front side, even if the end surface side of the workpiece W is formed in a complicated shape such as a comb tooth shape, one or two pressure sensors are provided. The pressure acting on the abutting member 49 side by the sheet 55 can be accurately detected.

  As described above, according to the embodiment of the present invention, as described above, even if the pressing force of the work W on the abutting member 49 side by the operator O is small, the one or two pressure sensor sheets 55 are used for the pressing. The pressure acting on the abutting member 49 side can be accurately detected. Therefore, according to the embodiment of the present invention, even when the workpiece W is thin and the workpiece W has low rigidity, the workpiece W is warped when the end surface of the workpiece W is abutted against the front surface of the abutting member 49. This can be sufficiently suppressed. Therefore, according to the embodiment of the present invention, even if the workpiece W is thin and the rigidity of the workpiece W is small, the positioning accuracy of the workpiece W in the front-rear direction is maintained and the workpiece W is highly accurately bent. It can be performed.

  Further, according to the embodiment of the present invention, as described above, the abutting member 49 is provided by one or two pressure sensor sheets 55 even if the shape of the end surface side of the workpiece W is a complicated shape such as a comb tooth shape. The pressure acting on the side can be detected accurately. Therefore, according to the embodiment of the present invention, high-precision bending can be stably performed on the workpiece W regardless of the shape on the end face side of the workpiece W.

  The present invention is not limited to the description of the above-described embodiment, and can be implemented in various other modes such as changing the number of abutting members 49 from two to one or three or more. . The scope of rights encompassed by the present invention is not limited to the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 Press brake 3 Upper die 5 Lower die 7 Main body frame 9 Side plate 11 Lower table 15 Upper table 19 Lifting hydraulic cylinder 21 Linear scale 23 Foot switch 25 Back gauge 27 Support member 31 First slider 33 Servo motor for back and forth movement 37 Lifting body 39 Lifting servo motor 41 Stretch 45 Second slider 47 Left / right movement servo motor 49 Abutting member 51 Abutting body 53 Elastic body 55 Pressure sensor sheet 57 Controller 59 Pattern setting unit 61 Pressure distribution analysis unit 63 Determination unit 65 Permit signal output unit 67 Stop signal output unit 67 and stop signal output unit 69 Indicator (notification unit)
P Abutting pattern SP Linear pattern IP Intermittent pattern RP Rectangular pattern D Pressure distribution (pressure distribution pattern)
W Work O Worker

Claims (9)

A lower table provided at the lower part of the main body frame and holding the lower mold on the upper side;
An upper table that is provided on the upper part of the main body frame so as to be movable relative to the lower table, and holds an upper mold on the lower side;
An elevator actuator for raising and lowering the upper table relative to the lower table;
A back gauge for positioning the workpiece in the depth direction with respect to the lower mold, having an abutting member provided on the back side of the lower table and movable in the depth direction and capable of abutting the end surface of the workpiece. And comprising
The said abutting member has the pressure sensor sheet | seat which detects the pressure which acts on the said abutting member side in the front side, The bending machine characterized by the above-mentioned. A pressure distribution analyzer for analyzing the pressure distribution acting on the abutting member side based on the detection result from the pressure sensor sheet;
A determination unit that determines whether or not the abutting pattern according to the pressure distribution and the workpiece information is adapted;
When it is determined that the pressure distribution and the abutment pattern are matched, a permission signal output unit that outputs a permission signal for allowing a relative lowering operation of the upper table is provided. The bending machine according to claim 1. A start switch for outputting a start signal for starting a relative lowering operation of the upper table;
The permission signal output unit outputs the permission signal when it is determined that the pressure distribution and the abutting pattern are matched on condition that an activation signal is input from the activation switch. The bending machine according to claim 2.   4. The bending machine according to claim 2, further comprising a notifying unit for notifying the determination result when it is determined that the pressure distribution and the abutting pattern do not match. 5.   When it is determined that the pressure distribution and the abutting pattern do not match between the start of the relative lowering operation of the upper table and the time when the upper mold reaches the pinching point, The bending machine according to any one of claims 2 to 4, further comprising a stop signal output unit that outputs a stop signal for stopping driving of the lifting actuator. Using a bending machine comprising a lower table provided at the lower part of the main body frame and an upper table provided at the upper part of the main body frame so as to be movable up and down relative to the lower table, A bending method for bending a workpiece by cooperation of an upper mold held on the side and a lower mold held on the upper side of the lower table,
Pressure distribution acting on the abutting member side based on the detection result from the pressure sensor sheet in a state where the end surface of the workpiece is abutted against the pressure sensor sheet held on the front side of the abutting member positioned in the depth direction Pressure distribution analysis step for analyzing
A determination step of determining whether or not the abutting pattern according to the pressure distribution and the workpiece information is adapted;
A permission signal output step of outputting a permission signal for permitting a relative lowering operation of the upper table when it is determined that the pressure distribution and the abutting pattern match. A characteristic bending method.   In the permission signal output step, it is determined that the pressure distribution and the abutting pattern are matched on condition that an activation signal for starting a relative lowering operation of the upper table has been input. In this case, the bending signal is output as the permission signal.   The bending method according to claim 6 or 7, further comprising a notifying step for notifying the determination result when it is determined that the pressure distribution and the abutting pattern do not match.   When it is determined that the pressure distribution and the abutting pattern do not match between the start of the relative lowering operation of the upper table and the time when the upper mold comes into contact with the upper surface of the workpiece. The bending method according to any one of claims 6 to 8, further comprising a stop signal output step of outputting a stop signal for stopping the driving of the lifting actuator.

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