JP4580779B2 - Sheet material bending method and sheet material bending machine - Google Patents

Description

  The present invention relates to a bending method and a plate material bending machine for bending a plate-shaped workpiece. More specifically, in the case of bending a workpiece, a bending process using an angle sensor for detecting a bending angle of the workpiece and a bending process in which the angle sensor cannot be used are mixed. Even if it exists, it is related with the bending method and the bending machine of the workpiece | work which can perform the bending which cannot use the said angle sensor correctly.

  Conventionally, when a plate-like workpiece is bent by a plate bending machine such as a press brake, the following procedure is generally used. That is, (1) The bending order until the workpiece becomes a product is determined. (2) Material information such as workpiece material, plate thickness, etc., punch used for workpiece bending, die mold information, machine information such as the amount of frame deflection during bending of the bending machine, and each Processing information such as a bending angle, a bending length, and a flange length in the bending process is input to the control device of the bending machine. (3) The relative stroke position of the punch with respect to the die is calculated for each bending process of the workpiece with reference to each information. (4) The workpiece is subjected to trial bending by controlling the relative stroke position of the punch based on the calculation result, and the calculated stroke position is corrected based on the result of the trial bending. (5) The workpiece is bent into a product by controlling the relative stroke position of the punch using the corrected stroke position.

  The trial bending is repeated several times until a predetermined angle is obtained with the corrected relative stroke position of the punch, and time and labor are required, and the punch is not affected by errors in the bending angle of the workpiece. In order to correct the relative stroke position accurately, there is a problem that a long experience is required.

  Therefore, the bending machine is equipped with an angle sensor for detecting the bending angle of the workpiece when bending the workpiece, and the relative stroke position of the punch is measured while actually measuring the bending angle of the workpiece with this angle sensor. Decisions are made.

Note that there is Patent Document 1 as a prior example that seems to be related to the present invention.
JP 2000-140943 A

  By the way, as described above, when bending a workpiece while actually measuring the bending angle of the workpiece with an angle sensor, depending on the workpiece, the flange length protruding outward from the V groove of the die is short and the angle The sensor may not be usable. In this case, there is a problem that trial bending is necessary as in the prior art.

  The bending apparatus described in Patent Document 1 includes a punch and a die for bending a plate-like workpiece so that the die can move in a relatively approaching and separating direction, and a relative stroke of the punch with respect to the die. A stroke position sensor for detecting a position is provided, and an angle sensor for detecting a bending angle of the workpiece when the workpiece is bent by the punch and die is provided.

  Then, the bending angle of the workpiece being bent is detected by the angle sensor, and the bending operation of the workpiece is stopped and the workpiece is taken out when the sandwiching angle in consideration of the springback amount is reached. When the angle sensor cannot be used, the D value (stroke) at the final target angle is calculated by bending simulation and mechanical system bending calculation formula using Young's modulus, n-th power hardening index, and plasticity coefficient, which are material constants calculated by trial bending. Position).

  That is, before bending the workpiece, it is necessary to obtain a material constant by performing trial bending in advance.

  The present invention has been made in view of the conventional problems as described above, and is provided with a punch and a die for bending a plate-like workpiece so as to be movable in a relatively approaching and separating direction, and with respect to the die. A plate bending machine having a stroke position sensor for detecting a relative stroke position of the punch, and an angle sensor for detecting a bending angle of the workpiece when the workpiece is bent by the punch and die. Is a bending method for bending a workpiece by calculating the relative stroke position of the punch with respect to the die based on punch and die mold information, workpiece material information and workpiece bending information. When the workpiece is bent for the first time based on the calculation result, the angle sensor detects the bending angle of the workpiece and The relative stroke position of the punch is detected by a stroke position sensor, and the related data between the stroke position and the bending angle is created, and the bending of the part where the angle sensor cannot be used for bending the workpiece. When machining, the difference between the calculation result and the related data is obtained, the stroke position of the calculation result is corrected based on the difference, and the relative stroke position of the punch is controlled by the corrected stroke position. Then, the workpiece is bent.

  In addition, a punch and die for bending a plate-like workpiece are provided so as to be able to move in a relatively approaching and separating direction, and a stroke position sensor is provided for detecting a relative stroke position of the punch with respect to the die. A plate material bending machine provided with an angle sensor for detecting a bending angle of a workpiece when the workpiece is bent by the punch and die, wherein the punch and die mold information, workpiece material information and workpiece Stroke position calculating means for calculating a relative stroke position of the punch with respect to the die based on the processing information for bending the sheet, and for controlling a relative stroke position of the punch with respect to the die according to a calculation result by the stroke position calculating means. Detected by the angle sensor when the workpiece is bent by the axis control means and the punch and die A related data memory for storing related data in which the bending angle and the stroke position detected by the stroke position sensor are associated, and whether or not the angle sensor can be used when bending the bending side of the workpiece. And when the angle sensor is not usable by the determination by the determination means, the difference between the related data stored in the related data memory and the calculation result of the stroke position calculation means is obtained to correct the stroke position of the calculation result. And a shaft control means for controlling the relative stroke position of the punch based on the stroke position corrected by the correction means.

In addition, a punch and die for bending a plate-like workpiece are provided so as to be able to move in a relatively approaching and separating direction, and a stroke position sensor is provided for detecting a relative stroke position of the punch with respect to the die. A bending sensor including an angle sensor for detecting a bending angle of the workpiece during bending of the workpiece by the punch and die and a load sensor for detecting a load (pressing force) at the time of bending. Stroke position calculating means for calculating a relative stroke position of the punch with respect to the die based on punch, die die information, workpiece material information and workpiece bending information, and the stroke position calculating means Shaft control means for controlling the relative stroke position of the punch with respect to the die according to the calculation result by Punch, the associated data memory for storing in association with each other and the load detected by folding the angle the load sensor and the stroke position detected by the bending angle and the stroke position sensor detected by the sensor during the machining of the workpiece by the dies, this Material constant calculation means for calculating an actual material constant with reference to data stored in the related data memory, and the stroke position calculation means for calculating a stroke position with reference to the material constant calculated by the material constant calculation means It is characterized by having.

  According to the present invention, the first bending process when bending the workpiece is a bending process in which an angle sensor can be used, and the relative stroke position of the punch at the first bending process is Data related to the bending angle of the workpiece can be created, which can be used as a reference for correction when bending a portion that cannot be used by the angle sensor. That is, the product can be bent without performing trial bending.

  As conceptually and schematically shown in FIG. 1, a plate material bending machine 1 according to the present embodiment is a bending machine such as a press brake, for example, and performs bending of a plate-like workpiece W. Therefore, the punch 3 and the die 5 are provided so as to be able to move in a direction in which the punch 3 and the die 5 are relatively approached and separated. It is optional to fix one of the punches 3 or the die 5 and move the other as in the case of a general press brake. However, in the present embodiment, the punch 3 is attached to the die 5. A relatively movable configuration is illustrated.

  In order to move the punch 3 toward and away from the die 5, the ram 7 to which the punch 3 is attached includes a fluid pressure mechanism such as a ball screw machine or a hydraulic cylinder rotated by a servo motor, for example. Connected to the actuating means 9. An appropriate stroke position detection sensor 11 such as a linear scale for detecting the relative stroke position (approaching / separating position) of the punch 3 with respect to the die 5 is provided at an appropriate position of the bending machine 1. And an appropriate load sensor 13 for detecting a load (pressing force) when the workpiece W is bent by the punch 3 and the die 5 is provided.

  As the load sensor 13, for example, a pressure sensor can be adopted when the ram actuating means 9 is actuated by a fluid pressure mechanism. A total etc. can be adopted. Furthermore, regardless of the mechanism for operating the ram operating means 9, it is possible to adopt a configuration in which a pressure detecting element such as a piezoelectric element is interposed between the punch 3 and the ram 7.

  Further, the bending machine 1 detects the flange portion of the workpiece W protruding outward from the V groove of the die 5 when the workpiece W is bent by the punch 3 and the die 5 to fold the workpiece W. An angle sensor 15 for detecting a bending angle is provided. In addition, since the structure of the bending machine 1 as mentioned above is well-known by the said patent document 1, etc., description about the mechanical structure in the bending machine 1 is abbreviate | omitted.

  In order to control the bending machine 1, the bending machine 1 is provided with a control device 17 such as a CNC. The control device 17 is connected to an input means 19 for inputting various data, and is connected to a bending order input device 21 for inputting the bending order of the workpiece when the product is bent. is there.

  The bending order input device 21 is composed of a CAM in a CAD / CAM system, and is used to bend a product when a three-dimensional drawing or development drawing graphic data is input from a CAD 23 as an input means. It has a function of determining the bending order. The bending order input device 21 is connected to a die shape data memory 25 storing the shape and dimension data of a die (punch, die) used for bending the workpiece W, and a bending machine. A machine information memory 27 storing the shape and dimension data of each part is connected. Further, a flange dimension memory 29 is connected which stores flange dimensions that can be used by the angle sensor 15 corresponding to each mold when the workpiece is bent.

  The bending order input device 21 is provided with a bending order extraction unit 31 for extracting all combinations of bending orders of the bent side of the product with reference to the graphic data of the product, and prevents interference between the workpiece and the mold. An interference check unit 33 for checking is provided. Further, the bending order input device 21 is provided with a proper bending order extraction unit 35 and a bending order data output unit 37 that outputs the extracted bending order data to the control device 17.

  With the above configuration, in the bending order input device 21, for example, when product shape data or product development data as shown in FIG. 3A or FIG. All the combinations of the bending orders of B1, B2, B3, and B4 are extracted. For all the bending orders extracted by the bending order extraction unit 31, the interference check unit 33 takes out the shape and dimension data of the die (punch, die) to be used from the die shape data memory 25, In addition to checking the interference between the mold and the work, data on the shape and dimensions of the machine is taken out from the machine information memory 27 to check the interference between the machine and the work.

  In this case, it is simulated (forward simulation) that the bending sides B1 to B4 of the development view of the product (see FIG. 3B) are gradually bent into the product (see FIG. 3A) according to the bending order. There is a case of performing an interference check and a case of performing an interference check by performing a simulation (reverse simulation) so that the product gradually opens from a product (see FIG. 3A) to a development view (see FIG. 3B). Whether to perform the reverse simulation or the reverse simulation is designated and input from the input means 35 such as a keyboard.

  If there is interference between the mold or the like and the workpiece in the interference check unit 33, the bending order including this interference is excluded, and only the bending order when there is no interference is extracted. When the interference check unit 33 extracts a bending order without interference, the appropriate bending order extraction unit 35 performs, for example, a moving operation such as a reversing operation or a rotating operation of the workpiece when the workpiece is bent. In consideration of the above, a plurality of bending orders capable of efficiently bending the workpiece are extracted.

  Thereafter, the flange dimension corresponding to the mold used for bending the bending side B2 corresponding to the flange F2 having a small flange dimension is taken out from the flange dimension memory 29, and the dimension of the flange F2 is extracted by the appropriate bending order extraction unit 35. Compared with When the flange dimension of the flange F2 is smaller than the flange dimension extracted from the flange dimension memory 29, the bending order in which the bending side B2 is included in the first bending process is excluded, and the remaining bending order is excluded. An arbitrary bending order is selected from the above, and an appropriate bending order is extracted.

  As described above, when an appropriate bending order is extracted by the appropriate bending order extraction unit 35, bending order data (bending order program) is output from the bending order data output unit 37. The bending order data output from the bending order data output unit 37 is input to the control device 17. As a method for inputting the bending order data from the bending order data output unit 37 to the control device 17, for example, the bending order data may be input via a communication unit, or the bending order data is stored in an appropriate storage unit, It is also possible to input bending order data to the control device 17 via this storage means.

  When a bending order program is input from the bending order input device 21 to the control device 17, stroke position calculating means 39 that calculates a relative stroke position of the punch 3 with respect to the die 5 in accordance with the bending order. And a parameter memory 41 in which the stroke position calculating means 39 stores parameters necessary for the calculation. The parameter memory 41 includes a machine information memory 41A, a material information memory 41B, a mold information memory 41C, and a machining information memory 41D.

  The machine information memory 41A stores data such as the amount of bending of the machine frame with respect to the pressurizing load when the workpiece W is bent, and the material information memory 41B stores the plate thickness, material, Data of tensile strength, n value (nth power hardening index), F value (plastic coefficient), E value (Young's modulus), and the like are stored. The die information memory 41C stores the tip angle of the punch 3, the punch tip R, the V groove angle of the die 5, the V width, the die shoulder R, and the like, and the machining information memory 41D stores the data. The bending angle, bending width (bending line length), flange length data, and the like of the workpiece W are stored.

  Further, the control device 17 is provided with an axis control means 43 for controlling the relative stroke position of the punch 3 with respect to the die 5 based on the calculation result of the stroke position calculation means 39, and this axis control means. When the workpiece W is bent by controlling the relative stroke position of the punch 3 with respect to the die 5 under the control of 43, the stroke position detected by the stroke position detection sensor 11 and the load sensor 13 are detected. A related data memory 45 for storing related data in which the applied load (pressing force) and the bending angle of the workpiece detected by the angle sensor 15 are associated is provided.

  Further, the control device 17 is provided with a discrimination means 47. The discriminating means 47 discriminates whether or not the bending side B2 of the workpiece W is bent when the workpiece W is bent according to the bending sequence of the workpiece W inputted from the bending sequence input device 21. It is determined whether or not the bending process (number of bendings) of the workpiece W is equal to the bending order of the bending side B2 input from the bending order input device 21. When it is determined by the determination means 47 that the bending side B2 is being bent, it is impossible to perform bending while detecting the bending angle of the workpiece W by the angle sensor 15, so the angle sensor A correction means 49 for correcting the calculation result of the stroke position calculation 39 is provided in order to bend the workpiece W without using 15.

  The correction means 49 obtains a difference between the calculation result of the stroke position calculation means 39 and the related data of the actual stroke position and the bending angle stored in the related data memory 45, and based on the obtained difference. The calculation result is corrected.

  In the above configuration, when product shape data is created in the CAD 23 and input to the bending order input device 21, the bending order input device 21 determines the bending order of the workpiece W as described above, and the bending order program is stored. Input to the control device 21 (steps S1 and S2). When the bending order of the workpiece W is input to the control device 17, the stroke position calculating means 39 calculates the relative stroke position of the punch 3 with respect to the die 5 for each bending side (step S3). The calculation of the stroke position by the stroke position calculating means 39 is to calculate the relative stroke position of the punch 3 for bending the workpiece W to the target angle with reference to various parameters stored in the parameter memory 41. It is. In this case, the stroke position is calculated in consideration of the springback amount of the workpiece W obtained in advance.

  The springback amount is obtained by detecting the return angle when the pressure applied by the punch 3 and the die 5 is released by the angle sensor 15 after the workpiece W is bent to a predetermined angle, for example, when the workpiece W is bent. It is something that can be done. As described above, the relative stroke position of the punch 3 is generally calculated based on various parameters, and the springback amount is obtained when the workpiece is bent. Therefore, the detailed description about calculating the relative stroke position of the punch 3 by the stroke position calculating means 39 is omitted.

  As described above, when the relative stroke position of the punch 3 to bend the workpiece W at a predetermined angle is calculated by the stroke position calculation means 39, the punch 3 relative to the die 5 is controlled under the control of the axis control means 43. The relative stroke position is controlled, and the first process (first time) is bent (step S4). At this time, the bending angle of the workpiece W is detected by the angle sensor 15, the bending process is performed while performing feedback control of the angle, and when the detected angle by the angle sensor 15 matches the predetermined angle, the first folding is performed. Song processing is stopped. In the first bending process, the pressure is almost zero and the workpiece W is held between the punch 3 and the die 5 to check the amount of springback, and the springback amount is set for the second and subsequent bending processes. It is desirable to correct.

  As described above, when the first bending process is performed, the stroke position detection sensor 11 detects the relative stroke position of the punch 3 every predetermined time, and the load sensor 13 detects the load every predetermined time. A bending angle is detected by the sensor 15 every predetermined time. The stroke position, load, and bending angle detected every predetermined time (sampling time) are stored in the related data memory 45 in association with each other.

  Next, the bending process after 2 processes is performed (step S5). In this case, it is determined by the determination means 47 whether or not the angle sensor 15 can be used during the second and subsequent steps, that is, whether or not angle feedback control is possible (step S6). The determination means 47 determines whether or not the order of the bending process (number of bendings) of the workpiece W is the order of the bending side B2 determined in advance by the bending order input device 21, whereby the angle sensor 15 Whether or not it can be used is indirectly determined.

  If it is determined in step S6 that the number of times does not correspond to the bending side B2, that is, if it is determined that the angle sensor 15 can be used, the folding while detecting the bending angle of the workpiece W by the angle sensor 15 as in step S4. Bending is performed (step S7). Thereafter, whether or not all the processes have been completed is determined by the determining means 47 (step S8). If not completed, the process returns to step S6, and if completed, the process ends.

  If it is determined in step S6 that the angle sensor 15 cannot be used, that is, if the bending side B2 is in the bending order, the process proceeds to step S9. That is, since the angle feedback is impossible when the bending side B2 is in the bending order, the target angle corresponding to the relative stroke position calculated by the stroke position calculating means 39 and the related data memory 45 are stored. The difference angle is calculated by the correction means 49 based on the difference from the measured angle corresponding to the relative stroke position (step S9). Based on this difference angle, the stroke position of the punch 3 relative to the die 5 is calculated again by the stroke position calculating means 39 (step S10).

  Based on the calculation result of the recalculation, the relative stroke position of the punch 3 is controlled under the control of the axis control means 43, and the bending side B2 is bent (step S11). Thereafter, the process proceeds to step S8 to repeat the operation as described above.

  As can be understood from the above description, when the workpiece W is bent while detecting the bending angle of the workpiece W using the angle sensor 15, the angle sensor 15 can be folded at an unusable portion. Even when bending is mixed, the bending can be performed accurately.

  By the way, in the above description, it has been explained that the difference angle is obtained from the difference between the target angle and the actually measured angle, and the relative stroke position of the punch 3 is recalculated. However, the control device 17 is provided with the material constant calculating means 51 to obtain the material constant of the actual workpiece W, and the stroke position calculating means 39 again calculates the relative stroke position of the punch 3 using this material constant. It is also possible. That is, the n value (nth power hardening index), the F value (plastic coefficient), and the E value (Young's modulus) as actual material constants can be obtained by the following equations as already known. is there.

n = Fn (Tp, t, St, θ)
F = Ff (Tp, t, P, θ, n)
E (Young's modulus) = Fe (Tp, t, Sb, θ, n, F)
Tp: Mold shape parameters (die V width, die angle, die shoulder R, punch tip R)
t: plate thickness St: final stroke θ: final bending angle P: final load Sb: spring back of material

It is explanatory drawing which showed notionally and schematically the bending machine which concerns on embodiment of this invention, and its control block. It is block explanatory drawing which showed notionally and schematically the structure of the bending order input device. It is explanatory drawing which shows an example of product shape data. It is a flowchart which shows operation | movement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet | seat bending machine 3 Punch 5 Die 9 Ram operation | movement means 11 Stroke position detection sensor 13 Load sensor 15 Angle sensor 17 Control apparatus 21 Bending order input apparatus 23 CAD (input means)
25 Mold Shape Data Memory 27 Machine Information Memory 29 Flange Dimension Memory 31 Bending Order Extraction Unit 33 Interference Checking Unit 37 Bending Order Data Output Unit 39 Stroke Position Calculation Unit 43 Axis Control Unit 45 Related Data Memory 47 Discriminating Unit 49 Correction Unit 51 Material Constant calculation means

Claims (3)

  A stroke position sensor for detecting a relative stroke position of the punch with respect to the die, and a punch and a die for bending a plate-like workpiece so as to be movable in a relatively approaching and separating direction. A bending method for bending a workpiece by a plate bending machine provided with an angle sensor for detecting a bending angle of the workpiece when the workpiece is bent by the punch and die. The relative stroke position of the punch with respect to the die is calculated based on die die information, workpiece material information, and workpiece bending information, and the workpiece is bent for the first time based on the calculation result. When the angle sensor detects the bending angle of the workpiece, the stroke position sensor detects the relative straw of the punch. When the position is detected and related data between the stroke position and the bending angle is created, and the workpiece is folded and the angle sensor cannot be used, the calculation result and the relation A difference from the data is obtained, the stroke position of the calculation result is corrected based on the difference, and the workpiece is bent by controlling the relative stroke position of the punch based on the corrected stroke position. A characteristic bending method.   A punch for bending a plate-shaped workpiece, a die that can be moved in a relatively approaching and separating direction, and a stroke position sensor for detecting a relative stroke position of the punch with respect to the die, A plate material bending machine equipped with an angle sensor for detecting a bending angle of a workpiece when a workpiece is bent by a punch or a die, and is used for folding punch and die mold information, workpiece material information, and a workpiece. Stroke position calculating means for calculating the relative stroke position of the punch with respect to the die based on bending information, and axis control for controlling the relative stroke position of the punch with respect to the die according to the calculation result by the stroke position calculating means And the folding detected by the angle sensor during bending of the workpiece by the punch and die. A related data memory that stores related data that associates the bend angle with the stroke position detected by the stroke position sensor, and a determination that determines whether or not the angle sensor can be used when bending the bending side of the workpiece. And a correction for correcting the stroke position of the calculation result by obtaining a difference between the related data stored in the related data memory and the calculation result of the stroke position calculation means when the angle sensor is unusable by the determination by the determination means And a shaft bending means for controlling the relative stroke position of the punch based on the stroke position corrected by the correction means. A punch for bending a plate-shaped workpiece, a die that can be moved in a relatively approaching and separating direction, and a stroke position sensor for detecting a relative stroke position of the punch with respect to the die, Bending machine provided with an angle sensor for detecting a bending angle of a workpiece at the time of bending the workpiece by a punch and die and also having a load sensor for detecting a load (pressing force) at the time of bending A stroke position calculating means for calculating a relative stroke position of the punch with respect to the die based on punch and die mold information, workpiece material information and work bending information, and calculation by the stroke position calculating means. Shaft control means for controlling the stroke position of the punch relative to the die according to the result, and the pan , The associated data memory for storing in association with each other and the load detected by folding the angle the load sensor and the stroke position detected by the bending angle and the stroke position sensor detected by the sensor during the machining of the workpiece by the dies, the relevant Material constant calculating means for calculating an actual material constant with reference to data stored in a data memory, and the stroke position calculating means for calculating a stroke position with reference to the material constant calculated by the material constant calculating means Bending machine characterized by

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