JP2006192498A - Bending method and bending machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coining/bending method and a bending machine by imparting pressing force to a work neither too much nor too little when performing the bending work of the planar work. <P>SOLUTION: The total pressing force is calculated by preliminarily determined pressing force per unit length required to the coining/bending with a first calculation means 29A on the basis of determined pressing force and the length of the bending line of a new work. The pressing force by right and left ram driving means 13 is calculated by a second calculation means 29B on the basis of the calculated total pressing force and the arranged position of the work to the bending machine. The strain of both side frames of the bending machine caused by the pressing force by the right and left ram driving means 13 and the inclined angle of the ram are calculated by a third calculation means 29C. According to the calculated result, the ram is preliminarily correctively inclined in the opposite direction and the coining/bending work of the work are performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bending method for bending a plate-like workpiece into a V shape by a bending machine such as a press brake, and a bending machine used for the bending method.

  A die having a V-shaped machining groove and a punch having a shape on the tip corresponding to the machining groove are mounted on a folding machine such as a press brake to bend a plate-like workpiece. When processing, there are processing methods such as air bending, bottoming and coining.

  The air bend folds a plate-like workpiece into a V-shape by pressing and bending the workpiece supported at two points on both shoulders of the V-shaped machining groove in the die with the tip of the punch. This is a bending method. In this air bend, although a workpiece can be bent at various desired angles by a pair of punches and dies, there is a problem that the amount of spring bag is large.

  Although the workpiece is bent by the bottoming, the workpiece is sandwiched between the V-shaped processing groove and the punch in the die, and when the workpiece is bent by 90 °, for example, the angle of the V groove is 88 ° or A 89 ° die is used, and bending is performed so that it becomes 90 ° when a springback is generated on the workpiece. In this case, although the amount of springback is smaller than that in the case of air bend, the amount of spring bag is not always stable and there is a problem in bending the workpiece with higher accuracy.

  The bending process of the workpiece by coining is to transfer the punch and die shape to the workpiece by applying a large pressing force about 5 to 8 times that of air bending to kill the workpiece spring bag. It is. Therefore, there is a problem that the frame rigidity has to be increased because large distortion is likely to occur in the frame in the bending machine.

In addition, there exists patent document 1 as a prior example which concerns on the bending machine which performs the bending process which performs an air bend and coining process. Patent Documents 2 and 3 are prior examples relating to air bends.
JP 2001-1049 A JP-A-8-155553 JP 7-39939 A

  In the invention according to Patent Document 1, when the workpiece is coined and bent by a bending machine such as a press brake, the value of the deviation counter exceeds the coining bending threshold stored in the NC device in advance. When the ram is lowered and the ram position exceeds the above threshold value, the lowering point of the coining bend ram is regarded as the bottom dead center and the ram lowering operation is terminated. Therefore, when coining bending is finished, it may be finished by bending corresponding to bottoming by bending, and a sufficient pressing force is applied to the workpiece to transfer the shape of the die and punch to the workpiece. There is a problem in that the coining bend may be terminated without any problem.

  The invention according to the description of Patent Document 2 is based on the premise of bending work by air bend and bottoming, and bending is performed by applying a large pressing force 5 to 8 times that of air bend to the work. It is not intended for coining.

  That is, if the concept of controlling the engagement position between the punch and die, such as air bend and bottoming, to bend the workpiece, is applied to the coining process, For example, if there is a change in the thickness of the workpiece due to a manufacturing error, the pressure may be insufficient or the pressure may be reduced. There is a problem that the die may be damaged if it is too large.

  In the invention according to the description of Patent Document 3, the workpiece is removed from the mold after the first bending of the workpiece, and the left and right angles of the workpiece are measured. By calculating and correcting the correction stroke amounts of the left and right drive shafts based on the difference, the accuracy of the bending angle at a plurality of points of the workpiece is improved. However, since the invention according to the description of Patent Document 3 relates to air bend processing and performs ram position control, it is difficult to apply to bottoming and coining processing as they are.

  The present invention has been made in view of the above-described problems, and a plate is formed between a V-shaped machining groove in a die mounted on a bending machine and a tip end side of a punch mounted on the folding machine. Is a bending method in which a workpiece is sandwiched, and the pressing force per unit length is determined by the pressing force required for bending the workpiece that has been previously bent. A required pressing force is calculated based on the length of a bending line of a new workpiece to be bent, and the new workpiece is bent by the calculated pressing force.

  In addition, a bending method in which a plate-shaped workpiece is sandwiched between a V-shaped processing groove in a die mounted on a bending machine and a tip end side of a punch mounted on the bending machine. Therefore, the applied pressure per unit length is determined by the applied pressure required for bending the workpiece that has been bent in advance, and the calculated applied pressure and the length of the fold line of the new workpiece to be bent from now are calculated. Calculate the required total applied pressure based on the above, or theoretically calculate the total applied pressure based on the die information, material information, and bending information. Based on the arrangement position, the pressure applied by the pressure means provided on the left and right sides of the bending machine is calculated, and the side frames of the folding machine are subjected to the pressure applied by the pressure means on the left and right sides. Calculate distortion The inclination angle of the ram that supports the die or punch is calculated based on the calculated distortion amount of both side frames, and the ram is inclined in the reverse direction in advance to correct the calculated inclination angle of the ram. The workpiece is bent by holding the state and driving the ram with pressure by the pressure means.

  In addition, a punch and a die for bending a plate-like workpiece are provided, and a ram for vertically moving one of the punch or the die is vertically movable. A bending machine comprising pressurizing means for pressurizing a workpiece between dies, input means for inputting the punch, die die information, workpiece material information and bending information, and bending of the workpiece The pressurizing means required for the pressurizing means is based on a database storing pressurizing force data per unit length required for machining, various information input from the input means, and pressurizing data stored in the database. An arithmetic means for calculating the pressure and a control means for controlling the pressurizing means based on the calculation result of the arithmetic means are provided.

  In addition, a punch and a die for bending a plate-like workpiece are provided, and a ram for vertically moving one of the punch or the die is vertically movable. A bending machine provided with pressure means for pressing a workpiece between dies on both the left and right sides; input means for inputting the punch, die mold information, workpiece material information and bending information; The pressurization based on a database storing pressure data per unit length required for bending various workpieces, various information input from the input means, and pressure data stored in the database The first calculating means for calculating the total pressing force required by the means, and the right and left pressurizing means based on the total pressing force calculated by the first calculating means and the arrangement position information of the workpiece with respect to the bending machine. A second calculation means for calculating the applied pressure, and a third calculation for calculating a distortion amount of both side frames in the bending machine and calculating an inclination angle of the ram based on a calculation result of the second calculation means. And the right and left pressurizing means are controlled to correct the inclination angle of the ram calculated by the third calculating means to the reverse tilt angle, and the left and right pressurizing means are controlled by the calculation result of the second calculating means. And a control means.

  In addition, a punch and a die for bending a plate-like workpiece are provided, and a ram for vertically moving one of the punch or the die is vertically movable. A bending machine comprising pressurizing means for pressurizing a work between dies, the input means for inputting punch, die mold information, work material information and bending information, and the mold Computation means for computing a pressing force required for bending a workpiece based on information, material information and bending information, and control means for controlling the pressurization means based on the computation result of the computation means. It is characterized by this.

  In addition, a punch and a die for bending a plate-like workpiece are provided, and a ram for vertically moving one of the punch or the die is vertically movable. A bending machine provided with pressure means for pressing a workpiece between dies on both the left and right sides; input means for inputting the punch, die mold information, workpiece material information and bending information; First calculation means for calculating a total pressing force required for bending the workpiece based on various information input from the input means, and the total pressing force calculated by the first calculation means and the workpiece with respect to the bending machine. Based on the arrangement position information, second calculation means for calculating the pressure applied to the right and left pressurization means, and on the calculation result of the second calculation means, the distortion amount of both side frames in the bending machine is calculated. You And a third calculating means for calculating the inclination angle of the ram, and controlling the right and left pressurizing means to correct the inclination angle of the ram calculated by the third calculating means to opposite inclination angles, and the second calculation. And a control means for controlling the left and right pressurizing means according to the calculation result of the means.

  According to the present invention, the pressurizing force per unit length is obtained by the pressurizing force required for bending the work that has been previously bent, and the pressurizing force per unit length and the length of the bending line of the work When the workpiece is pressed with the punch and die, the workpiece is pressed with the pressure determined as described above, so that the workpiece can be pressed without excess or deficiency. The bending process for transferring the die shape onto the workpiece can be performed accurately.

  Referring to FIG. 1, a press brake 1 as an example of a bending machine for bending a plate-shaped workpiece W includes C-shaped left and right side frames 3. On the front side, an upper table 5 and a lower table 7 are provided so as to face each other vertically. A die (lower die) 9 is mounted on the upper portion of the lower table 7, and a punch (upper die) for bending the workpiece W in cooperation with the die 9 is attached to the lower portion of the upper table 5. 11 is attached.

  As is well known, a V-shaped machining groove (V-groove) is formed on the upper side of the die 9 for bending the workpiece W, and the tip end side (lower end side) of the punch 11 is formed. ) Is formed in a V shape corresponding to the V groove in the die 9. Therefore, the workpiece W can be bent into a V shape by disposing the workpiece W between the die 9 and the punch 11 and engaging the punch 11 and the die 9.

  As described above, in order to bend the workpiece W by engaging the punch 11 and the die 9, an appropriate one of the upper table 5 or the lower table 7 is provided as a ram so as to be movable up and down. In this example, an upper table 5 is provided as a ram so as to be movable up and down. In order to move the upper table (ram) 5 up and down, the left and right side tables 3 include, for example, a hydraulic cylinder and a ball screw mechanism. A ram driving means (pressurizing means) 13 having an appropriate configuration is attached. Therefore, by driving the left and right ram driving means 13 as the pressurizing means and lowering the ram 5, the work W can be pressurized by the die 9 and the punch 11 to be bent. .

  As described above, when the ram 5 is moved up and down, the position detection means 15 such as a linear sensor for detecting the vertical movement position of the left and right sides of the ram 5 is used to detect the vertical movement position of the punch 11 relative to the die 9. It is provided on both sides. Furthermore, appropriate bending pressure detection means 17 such as a pressure sensor for detecting the pressure applied to the workpiece W by the left and right ram driving means (pressurizing means) 13 when the workpiece W is bent is provided separately on the left and right sides. ing. Furthermore, bending angle detection means 19 for detecting the bending angle of the workpiece W is provided at an appropriate number of locations on the lower table 7. Further, the press brake 1 is provided with a control device 21 such as a CNC device for controlling the entire operation.

  In the above configuration, the ram driving means 13 is controlled under the control of the control device 21 to lower the ram 5, and the workpiece W on the die 9 is pressed into the V groove of the die 9 by the punch 11. The bending process is performed. In this case, when the three points of the shoulders of the V groove in the die 9 and the tip of the punch 11 are in contact with the workpiece W, the bending is performed by air bending, and the V groove of the die 9 and the punch 11 are bent. When the workpiece W is sandwiched on the tip end side, the bending process is performed by bottoming. The bending process that presses the workpiece W more strongly from the bottoming state and transfers the V shape of the die 9 and the punch 11 to the workpiece W is a folding process by coining.

  By the way, conventionally, coining processing is performed by applying a large pressing force about 5 to 8 times the pressing force at the time of air bending to the workpiece W, and the necessary minimum pressing force is always applied to the workpiece W. However, the pressure applied to the workpiece W may be larger than necessary, and the die 9 may be damaged in some cases.

  Therefore, in the bending machine 1 according to the present embodiment, when the workpiece W is bent by bottoming or coining, an appropriate pressure is always applied to the workpiece W to perform bottoming or coining. It is configured to obtain.

  That is, as shown in FIG. 2, the control device 21 is connected with an input means 23 for inputting, for example, die 9 and punch 11 die information, workpiece W material information and bending information. The position detecting means 15, the applied pressure detecting means 17, and the bending angle detecting means 19 are connected.

  The mold information includes a minute radius of the tip of the punch 11, an angle on the tip side, a V width dimension of the V groove in the die 9, an angle of the V groove, a minute radius of the shoulder of the V groove, and the like. The material information of the workpiece W includes a plate thickness, a material, and the like, and the bending information includes a bending angle, a bending length, a bending position (arrangement position in the left-right direction in the bending machine 1), and the like.

  The control device 21 is provided with a database 25 and a search means 27 for searching the database 25 based on information input from the input means 23. In the database 25, when the bottoming or coining of the workpiece W such as a test piece is experimentally performed by the punch 11 and the die 9 which make a pair, the unit length required for the bottoming or coining of the workpiece W is measured. The data of proper pressure is stored. The appropriate pressing force data is data in which die information of the punch 11 and die 9 making a pair is associated with material information of the material and thickness of the workpiece W. Therefore, if the mold information such as the die number of the punch 11 and die 9 making a pair or the punch 11 and the die 9 is set, and the material information such as the material of the workpiece W and the plate thickness are known, the appropriate addition The pressure data can be searched.

  Further, the control device 21 is provided with a calculation means 29 for performing various calculations based on various information input from the input means 23 and pressure data retrieved from the database 25. Control means 31 for controlling the ram drive means 13 based on the calculation result of the calculation means 29 is provided.

  In the configuration as described above, when the mold information, material information and bending information are input from the input means 23 (steps S1, S2, S3), the search of the database 25 is performed by the search means 27 (step S4). Corresponding to the input die (punch 11, die 9) and workpiece W, the appropriate pressure per unit length when performing bottoming or coining is retrieved.

  As described above, when the appropriate pressing force per unit length is retrieved, the total pressing force when the workpiece W is bottomed or coined based on the appropriate pressing force and the bending length of the material is calculated in the calculation means 29. The target pressure applied by the left and right ram driving means 13 is calculated by the first calculating means 29A (step S5) and the position information (arrangement position information) in the left and right directions for performing the bottoming process or coining process of the workpiece W. 2 is computed by the computing means 29B (step S6).

  In other words, when bottoming or coining is performed with the workpiece W arranged in the center in the left-right direction, the target pressure applied by the left and right ram driving means 13 is equal, for example, the workpiece W is arranged on the right side of the center. When bottoming or coining is performed, the target pressure applied by the right ram drive means 13 is greater than the target pressure applied by the left ram drive means 13. In this case, the total pressure is distributed so as to be inversely proportional to the distance from the central portion of the workpiece W in the left-right direction to the left and right ram driving means 13.

  As described above, when the target pressing force by the left and right ram driving means 13 is calculated, the reaction force when the target pressing force is applied to the workpiece W by the left and right ram driving means 13 respectively. The amount of deflection (distortion) of the left and right side frames 3 is calculated by the third calculation means 29C, and the inclination angle of the ram 5 is calculated based on the calculation result (step S7). The inclination angle of the ram 5 is an inclination angle generated by a reaction force when coining the workpiece W. Therefore, in order to correct the calculated inclination angle in advance, the inclination of the ram 5 is reversed with respect to the inclination angle. The inclination is corrected (step S8). The inclination angle of the ram 5 is corrected by correcting the inclination of the calculation result by the third calculating means 29C to a reverse inclination, and individually driving the left and right ram driving means 13 by the control means 31 based on this correction. It is what is said. The inclination angle of the ram 5 can be known based on the detection value of the left and right position detection means 15.

  As described above, after correcting the inclination angle of the ram 5, the left and right ram driving means 13 are respectively actuated (driven) under the control of the control device 31 while maintaining the corrected inclination angle. It descends and starts bottoming or coining of the workpiece W (step S9). Thereafter, the pressure applied by the left and right ram driving means 13 is detected by the pressure detection means 17, respectively, and it is determined whether or not the detected pressure is equal to the target pressure (step S10). When the pressure and the target pressing force are equal, the bottoming process or coining process is terminated assuming that an appropriate pressing force is applied to the workpiece W for the bottoming process or coining process (step S11).

  As will be understood from the above description, when performing bottoming or coining of the workpiece W, the bottoming or coining of the workpiece W is performed based on the appropriate pressure per unit length stored in the database 25 in advance. Therefore, the bottoming or coining of the workpiece W is always performed with an appropriate pressure because the total pressing force required for the right and left ram driving means 13 is obtained. The processing can be performed, the applied pressure is neither too small nor too large, and efficient bottoming or coining can be performed without damaging the die.

  Further, when the workpiece W is unevenly distributed in the left-right direction, the inclination angle of the ram 5 is obtained, and the ram 5 is inclined in advance reversely so as to correct the inclination angle, and the workpiece W is bottomed or coined. Therefore, compared with the case where the inclination of the ram 5 is corrected at the time of the bottoming process or coining process, the inclination angle of the ram 5 can be corrected easily and accurately, and the accuracy is high. A bottoming process or a coining process can be performed.

  By the way, the present invention is not limited to the embodiment as described above, and can be implemented by making appropriate changes. That is, in the above description, the case where the data of the pressing force per unit length required for workpiece bottoming or coining is stored in the database is exemplified. However, the following configuration is also possible.

  That is, a calculation means for calculating the pressurizing force required for the bottoming process or coining process of the workpiece based on punch, die mold information, workpiece material information and bending information, the mold information, The material information and bending information are input from the input means 23, and the total applied pressure required for workpiece bottoming or coining is calculated. Based on the calculated total applied pressure and the work placement position information, the applied pressure required for the right and left pressurizing means 13 is calculated, and the inclination is reversed to correct the inclination of the ram as in the above-described embodiment. Thus, the pressure control of the right and left pressurizing means 13 can be performed.

  That is, in performing the bottoming process or coining process of the workpiece, in order to control the pressure of the pressurizing means 13, even if the total applied pressure is calculated based on the pressure data stored in the database, the die information Based on the material information and bending information, the total applied pressure may be theoretically calculated by a theoretical formula (empirical formula) stored in advance in memory.

  By the way, as the work W to be bent, the fold line of the work W is not always continuous. For example, as shown in FIG. In some cases, the hole H may be provided. In this case, the lengths of the fold lines corresponding to the protrusions P1, P2, and P3 are B1, B2, B3, and B4, respectively, and the fold line length A is (B1 + B2 + B3 + B4).

Here, B is the total length of the fold line extending from the protrusions P1 to P4, BP is the dimension from the center O of the bending machine to the center of the fold line B, and the protrusion P1. If the dimensions from one end side to the center of each fold line B1, B2, B3, B4 are L1, L2, L3, and L4, respectively,
AP = {(B1 * (L1-B / 2 + BP))
+ (B2 * (L2-B / 2 + BP))
+ (B3 * (L3-B / 2 + BP))
+ (B4 * (L4-B / 2 + BP))} / A
It becomes. Therefore, when the bending process is performed along each of the bending lines B1, B2, B3, and B4, it is assumed that the total applied pressure when performing the bending process of the bending line length A acts on the bending center of gravity position AP. The pressure applied to the left and right pressurizing means 13 is calculated.

  As described above, the actual bending length is calculated, the actual bending center of gravity position is calculated, and the total pressing force acts on this actual bending center of gravity position. By calculating and distributing the pressure, the inclination correction of the ram 5 is corrected in accordance with the actual bending process, and a more accurate bending process can be performed.

  In the description of the present embodiment, the correction of the inclination of the ram 5 has been mainly described. However, the crowning correction of the ram 5 or the lower table 7 (the correction that the central portion of the lower table 7 is curved in a convex shape upward). ), It is desirable to calculate the actual bending length and bending center of gravity as described above, and to perform the crowning correction in consideration of the pressurizing force required for the right and left pressurizing means.

It is a conceptual and schematic explanatory drawing of the bending machine which concerns on embodiment of this invention. It is a functional block diagram which shows the function of a control apparatus. It is a flowchart for demonstrating operation | movement. It is explanatory drawing of the actual bending line length and bending center-of-gravity position by the shape of a workpiece | work.

Explanation of symbols

1 Press brake (bending machine)
3 Side frame 5 Upper table (ram)
7 Lower table 9 Die (lower mold)
11 Punch (upper die)
13 Ram driving means (pressurizing means)
17 Pressurizing force detection means 21 Control device 25 Database 27 Search means 29 Calculation means 31 Control means

Claims (6)

  A bending method in which a plate-shaped workpiece is sandwiched between a V-shaped machining groove in a die attached to a bending machine and a tip end side of a punch attached to the bending machine. Based on the pressure applied per unit length based on the pressure required to bend the workpiece that was previously bent, and based on the calculated pressure and the length of the fold line of the new workpiece to be bent from now A bending method characterized by calculating a required pressing force and bending the new workpiece with the calculated pressing force.   A bending method in which a plate-shaped workpiece is sandwiched between a V-shaped machining groove in a die attached to a bending machine and a tip end side of a punch attached to the bending machine. Based on the pressure applied per unit length based on the pressure required to bend the workpiece that was previously bent, and based on the calculated pressure and the length of the fold line of the new workpiece to be bent from now Calculate the required total applied pressure, or theoretically calculate the total applied pressure based on mold information, material information and bending information, and place the new workpiece on the calculated bending force and the bending machine. Based on the above, the pressure applied by the pressure means provided on the left and right sides of the bending machine is calculated, and the amount of distortion of both side frames in the bending machine due to the pressure applied by the pressure means on the left and right sides To calculate The inclination angle of the ram that supports the die or punch is calculated according to the calculated distortion amount of both side frames, the ram is inclined in advance in the opposite direction in order to correct the calculated inclination angle of the ram, and this inclined state is obtained. A bending method characterized in that the workpiece is bent by holding and driving the ram by the pressing means.   A punch and a die for bending a plate-shaped workpiece are provided, and a ram for vertically moving one of the punch or die is vertically movable. The ram is moved up and down to move the punch and die. A bending machine equipped with a pressurizing means for pressurizing a work in between, input means for inputting the punch, die mold information, work material information and bending information, and bending work The pressurizing force required for the pressurizing means based on the database storing the pressurizing force data per unit length required, various information input from the input means, and the pressurizing data stored in the database. A bending machine comprising: a calculating means for calculating; and a control means for controlling the pressurizing means based on a calculation result of the calculating means.   A punch and a die for bending a plate-shaped workpiece are provided, and a ram for vertically moving one of the punch or die is vertically movable. The ram is moved up and down to move the punch and die. A bending machine having pressurizing means for pressurizing a workpiece between the left and right sides, an input means for inputting the punch, die mold information, workpiece material information and bending information, and various workpieces The pressurizing means is based on a database storing pressurization data per unit length required for bending, and various information input from the input means and pressurization data stored in the database. Necessary for the right and left pressurizing means based on the first calculating means for calculating the required total pressing force, the total pressing force calculated by the first calculating means and the arrangement position information of the workpiece with respect to the bending machine. Second calculating means for calculating pressure, and third calculating means for calculating the distortion amount of both side frames in the bending machine and calculating the inclination angle of the ram based on the calculation result of the second calculating means. The left and right pressurizing means are controlled to correct the ram inclination angle calculated by the third arithmetic means to the opposite inclination angle, and the left and right pressurizing means are controlled based on the calculation result of the second arithmetic means. And a bending machine.   A punch and a die for bending a plate-shaped workpiece are provided, and a ram for vertically moving one of the punch or die is vertically movable. The ram is moved up and down to move the punch and die. A bending machine provided with a pressurizing means for pressurizing a workpiece in between, input means for inputting the punch, die mold information, workpiece material information and bending information, and the mold information; Computation means for computing a pressurizing force required for bending a workpiece based on material information and bending information, and control means for controlling the pressurization means based on the computation result of the computation means. Folding machine featuring.   A punch and a die for bending a plate-shaped workpiece are provided, and a ram for vertically moving one of the punch or die is vertically movable. The ram is moved up and down to move the punch and die. A bending machine provided with pressurizing means on both the left and right sides for pressurizing a work in between, the input means for inputting the punch, die mold information, work material information and bending information, and the input First calculation means for calculating the total pressure required for bending the workpiece based on various information input from the means, the total pressure calculated by the first calculation means, and the position of the workpiece relative to the bending machine The second calculation means for calculating the pressure applied to the right and left pressurization means based on the information, and the amount of distortion of both side frames in the folding machine based on the calculation result of the second calculation means. Third calculating means for calculating the inclination angle of the ram, and controlling the right and left pressurizing means to correct the inclination angle of the ram calculated by the third calculating means to opposite inclination angles, and the second calculating means And a control means for controlling the right and left pressurizing means according to the result of the calculation.

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