Bending machine and bending method

Abstract

A bending machine (1) is provided with a hydraulic cylinder (9L, 9R) that freely adjusts the inclination of a left and right of an upper table (7), i.e., an inclination state; an eccentric shaft unit (19L, 19R) that bends a part of a lower table (5); and a control device (30). The control device (30) sets the inclination state of the upper table (7), and sets the bending state of the lower table (5) in a manner following the inclination state of the upper table (7), and performs local bending in which a pressing range in which a workpiece (W) is pressed in the entire region of a left and right direction (X) using an upper die (8) and a lower die (6) is limited. The control device (30) switches the combination of the inclination state of the upper table (7) and the bending state of the lower table (5), and repeatedly performs local bending while shifting the limited pressing range, thereby performing entire region bending in which the workpiece (W) is pressed in the entire region of the left and right direction (X).

Description

Technical Field

[0001] This disclosure relates to a bending machine and a bending method. Background Technology

[0002] A bending machine is known that applies pressure to a workpiece between an upper and lower die by moving an upper worktable relative to a lower worktable, thereby bending a plate-shaped workpiece. During bending, the pressure reaction force acts on the upper and lower worktables via the workpiece held by the upper and lower dies. This pressure reaction force causes deflection deformation on the upper and lower worktables, thus reducing the uniformity accuracy of the workpiece. Here, uniformity accuracy refers to the accuracy of the bending angle of the workpiece along the bending line of the workpiece.

[0003] For example, Patent Document 1 discloses a bending machine that, in addition to the left and right lifting mechanisms for raising and lowering the upper worktable, also has a convex surface processing mechanism in the center of the lower worktable to correct the deflection of the lower worktable. According to this bending machine, by using the convex surface processing mechanism to bend the central part of the lower worktable upward into a convex shape to counteract the deflection of the lower worktable, the uniformity accuracy of the workpiece can be improved.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 5-329549 Summary of the Invention

[0007] However, in bending processes such as bending workpieces with long curves that cover the entire area of ​​the worktable, sometimes sufficient uniformity of accuracy cannot be obtained in the entire area of ​​the workpiece in the left-right direction.

[0008] One aspect of the bending machine disclosed herein includes: a movable worktable on which a first mold is mounted in a left-right direction; and a fixed worktable opposite to the movable worktable in a vertical direction, on which a second mold is mounted in a left-right direction. The workpiece is bent by moving the movable worktable in a vertical direction to apply pressure between the first mold and the second mold. The machine also includes: a lifting mechanism that moves the movable worktable in a vertical direction and freely adjusts the left-right tilt (i.e., tilt state) of the movable worktable; a convex surface processing mechanism that bends a portion of the fixed worktable; and a control device that controls the lifting mechanism and the convex surface processing mechanism. The control device sets the tilt state of the movable worktable and sets the bending state of the fixed worktable along the tilt state of the movable worktable, performing partial bending with pressure applied to a limited area than the entire left-right region of the first and second molds. In addition, the control device switches between the tilt state of the movable worktable and the bending state of the fixed worktable, and repeatedly performs the local bending while shifting the defined pressure range, thereby performing bending of the entire area of ​​the workpiece in the left-right direction.

[0009] According to this structure, instead of applying pressure to the entire bending area of ​​the workpiece all at once, pressure is applied to a defined pressure range. At this time, the movable worktable is tilted according to the pressure range, and the fixed worktable is bent along this tilt, thereby suppressing deflection of the worktable within the pressure range. Since deflection of the worktable within the pressure range is suppressed, the distance between the front ends of the first and second dies during pressure application can be kept constant. As a result, the bending angle of the entire pressure range pressured by the dies is made consistent. Furthermore, by repeatedly performing local bending to shift the pressure range, pressure can be applied to the entire area in the left-right direction. At this time, the bending angle is maintained within each pressure range where local bending occurs; therefore, by bending the entire area, the bending angle of the entire area in the left-right direction of the workpiece is made consistent.

[0010] According to one aspect of this disclosure, sufficient uniformity of accuracy can be achieved over the entire area in the left-right direction of the workpiece. Attached Figure Description

[0011] Figure 1 This is an explanatory diagram schematically showing the structure of the bending machine according to this embodiment.

[0012] Figure 2 This is an explanatory diagram showing the first step of the bending process performed by the bending machine.

[0013] Figure 3 This is an explanatory diagram showing the second step of the bending process performed by the bending machine.

[0014] Figure 4 This is an explanatory diagram showing the third step of the bending process performed by the bending machine.

[0015] Figure 5 This is an explanatory diagram showing the fourth step of the bending process performed by the bending machine.

[0016] Figure 6 This is an explanatory diagram showing the fifth step of the bending process performed by the bending machine.

[0017] Figure 7 This is an explanatory diagram showing the sixth step of the bending process performed by the bending machine.

[0018] Figure 8 This is an explanatory diagram showing the seventh step of the bending process performed by the bending machine.

[0019] Figure 9 This is an explanatory diagram showing the eighth step of the bending process performed by the bending machine.

[0020] Figure 10 This is an explanatory diagram showing the ninth step of the bending process performed by the bending machine.

[0021] Figure 11 This is an explanatory diagram showing the tenth step of the bending process performed by the bending machine.

[0022] Figure 12 This is an explanatory diagram showing the eleventh step of the bending process performed by the bending machine.

[0023] Figure 13 This is an explanatory diagram showing the angle measurement points on the workpiece.

[0024] Figure 14 This is a diagram showing the input screen used to input angle measurement results.

[0025] Figure 15 This is an explanatory diagram showing an example of a workpiece that will be processed.

[0026] Figure 16 This is an explanatory diagram showing the action of applying pressure to a workpiece alternately from left to right.

[0027] Figure 17 This is an explanatory diagram showing the action of applying pressure to a workpiece alternately from left to right. Detailed Implementation

[0028] Hereinafter, the bending machine and bending method of this embodiment will be described with reference to the accompanying drawings.

[0029] Figure 1 This is an explanatory diagram schematically illustrating the structure of the bending machine according to this embodiment. In the following description, to define the bending machine, the left-right direction X, the front-back direction Y, and the up-down direction Z are used. The left-right direction X and the front-back direction Y correspond to two directions orthogonal in the horizontal direction, and the up-down direction Z corresponds to the vertical direction. However, these directions are merely used for convenience in explaining the bending machine in this embodiment.

[0030] The bending machine 1 of this embodiment includes: an upper worktable 7 (an example of a movable worktable) on which an upper die 8 (an example of a first die) is mounted along the left-right direction X; and a lower worktable 5 (an example of a fixed worktable) opposite the upper worktable 7 in the vertical direction Z, on which a lower die 6 is mounted along the left-right direction X. The bending machine 1 moves the upper worktable 7 along the vertical direction Z to apply pressure to the workpiece between the upper die 8 and the lower die 6, thereby performing bending processing on the workpiece.

[0031] The bending machine 1 includes: hydraulic cylinders 9L and 9R (an example of a lifting mechanism) that move the upper worktable 7 in the vertical direction Z and freely adjust the left and right tilt of the upper worktable 7, i.e., its tilt state; eccentric shaft units 19L and 19R (an example of a convex surface processing mechanism) that bend a portion of the lower worktable 5; and a control device 30 that controls the hydraulic cylinders 9L and 9R and the eccentric shaft units 19L and 19R. The control device 30 sets the tilt state of the upper worktable 7 and sets the bending state of the lower worktable 5 along the tilt state of the upper worktable 7, performing local bending with pressure applied to a limited pressure range than when pressure is applied to the workpiece in the left and right direction X using the upper die 8 and lower die 6. The control device 30 switches between the combination of the tilt state of the upper worktable 7 and the bending state of the lower worktable 5, repeatedly performing local bending while shifting the limited pressure range, thereby performing full-area bending with pressure applied to the workpiece W in the left and right direction X.

[0032] The detailed structure of the bending machine 1 is described below. The bending machine 1 is, for example, a machine for bending sheet-shaped workpieces such as metal sheets. The bending machine 1 is, for example, a plate bending machine, which bends the workpiece by the cooperation of an upper die 8 such as a punch and a lower die 6 such as a die.

[0033] The bending machine 1 has a lower worktable 5, an upper worktable 7, left and right hydraulic cylinders 9L and 9R, left and right eccentric shaft units 19L and 19R, and a control device 30.

[0034] The bending machine 1 has left and right side frames 3L and 3R, which are separated in the left-right direction X. An upper worktable 7 extends in the left-right direction X and is supported on the upper front part of the side frames 3L and 3R. The upper worktable 7 is configured to move in the vertical direction Z. A lower worktable 5 extends in the left-right direction X and is supported on the lower front part of the side frames 3L and 3R.

[0035] An upper mold support is provided on the lower side of the upper worktable 7 to detachably hold the upper mold 8. A support groove for inserting the base of the upper mold 8 is formed along the left-right direction X in the upper mold support. The upper mold support has a clamping mechanism for fixing the upper mold 8 relative to the upper worktable 7.

[0036] A lower mold support is provided on the upper side of the lower worktable 5 to detachably hold the lower mold 6. A support groove for inserting the base of the lower mold 6 is formed along the left-right direction X on the lower mold support. The lower mold support has a clamping mechanism to fix the lower mold 6 relative to the lower worktable 5.

[0037] The left and right hydraulic cylinders 9L and 9R are respectively located on the upper left and right sides of the side frames 3L and 3R. The left and right hydraulic cylinders 9L and 9R function as a lifting mechanism to move the upper worktable 7 in the vertical Z direction. The left and right hydraulic cylinders 9L and 9R can be controlled independently. By independently controlling the left and right hydraulic cylinders 9L and 9R, the left and right tilt of the upper worktable 7 can be adjusted. Furthermore, the lifting mechanism is not limited to using the left and right hydraulic cylinders 9L and 9R; it can also be composed of left and right electric motors, etc.

[0038] The tilting states of the upper worktable 7 include a tilting state to the lower left and a tilting state to the lower right. A tilting state to the lower left means that the left side of the upper worktable 7 is closer to the lower worktable 5 than its right side; in this embodiment, it means that the left side of the upper worktable 7 tilts downwards more than its right side. Conversely, a tilting state to the lower right means that the right side of the upper worktable 7 is closer to the lower worktable 5 than its left side; in this embodiment, it means that the right side of the upper worktable 7 tilts downwards more than its left side. Furthermore, a tilting state to the lower left simply requires that the left side of the upper worktable 7 tilts downwards more than its right side; the degree (angle) of the tilt of the upper worktable 7 relative to the horizontal can be arbitrarily set within the movable range of the upper worktable 7. The same applies to the tilting state to the lower right.

[0039] In addition, the tilt state of the upper worktable 7 includes not only tilting to either the left or right, but also the basic posture of the upper worktable 7. The basic posture of the upper worktable 7 refers to the state in which the height of the left side of the upper worktable 7 is the same as the height of its right side, and the upper worktable 7 is horizontal from left to right.

[0040] A front plate 11 and a rear plate 13 are respectively provided on the front and rear sides of the lower worktable 5. The front plate 11 and the rear plate 13 are integrally mounted on the lower worktable 5 via left and right pivots 15L and 15R that run through the front and rear direction Y.

[0041] Symmetrically positioned to the left and right of the center position in the left-right direction X of the lower worktable 5 are through holes 17L and 17R that extend along the front-back direction Y through the front plate 11, the lower worktable 5, and the rear plate 13. Eccentric shaft units 19L and 19R are disposed within the through holes 17L and 17R. When viewed in the left-right direction X, the left eccentric shaft unit 19L is positioned closer to the center position of the lower worktable 5 than the left hydraulic cylinder 9L. Similarly, when viewed in the left-right direction X, the right eccentric shaft unit 19R is positioned closer to the center position of the lower worktable 5 than the right hydraulic cylinder 9R.

[0042] Eccentric shaft units 19L and 19R are fixed to the front plate 11 and the rear plate 13. By rotating the eccentric shafts, eccentric shaft units 19L and 19R can press the lower worktable 5 upward relative to the front plate 11 and the rear plate 13. Eccentric shaft units 19L and 19R function as a convex surface machining mechanism that bends a portion of the lower worktable 5 upward into a convex shape by pressing it upward. Furthermore, the convex surface machining mechanism is not limited to the structure using left-right eccentric shaft units 19L and 19R; it can also be constructed using left-right hydraulic cylinders or the like.

[0043] The left and right eccentric shaft units 19L and 19R can be controlled independently. By independently controlling the left and right eccentric shaft units 19L and 19R, the bending state of the lower worktable 5 can be adjusted. The adjustment of the bending state includes adjusting the bending position, bending shape, and bending degree of the lower worktable 5, such as the left side, center, and right side. That is, by independently controlling the left and right eccentric shaft units 19L and 19R, the bending shape of the lower worktable 5 can be set to a symmetrical shape or an asymmetrical shape.

[0044] The control device 30 may include, for example, a computer such as a numerically controlled machine tool (NC). The computer primarily consists of a hardware processor (CPU), memory, and various interfaces. The memory and various interfaces are connected to the hardware processor via a bus. A predetermined computer program is installed in the computer. The hardware processor executes the computer program, and the computer performs the functions of the control device 30.

[0045] The control device 30 controls the movement of the bending machine 1. Specifically, the control device 30 controls the left and right hydraulic cylinders 9L and 9R and the left and right eccentric shaft units 19L and 19R. By controlling the left and right hydraulic cylinders 9L and 9R and the left and right eccentric shaft units 19L and 19R, the control device 30 can control the vertical movement of the upper worktable 7 in the Z direction, the tilting state of the upper worktable 7, and the bending state of the lower worktable 5.

[0046] In the bending machine 1 with this structure, a plate-shaped workpiece is positioned on a lower die 6 mounted on the lower worktable 5. The control device 30 lowers the upper worktable 7 toward the lower worktable 5. As a result, pressure is applied to the workpiece between the upper die 8 and the lower die 6, and the workpiece is bent at the desired target bending angle through the cooperation of the upper die 8 and the lower die 6.

[0047] As one of the features of this embodiment, the control device 30 sets the tilt state of the upper worktable 7 and sets the bending state of the lower worktable 5 in a manner that follows the tilt state of the upper worktable 7. Furthermore, the control device 30 performs local bending by applying pressure within a pressure range that is limited to the pressure range when the workpiece is pressured in the entire area of ​​the left-right direction X using the upper mold 8 and the lower mold 6.

[0048] Furthermore, the control device 30 switches between the tilt state of the upper worktable 7 and the bending state of the lower worktable 5, repeatedly performing local bending while shifting the limited pressure range, thereby bending the entire area of ​​the workpiece W under pressure in the left-right direction X. Then, the control device 30 repeatedly performs the entire area bending multiple times, bending the workpiece in stages until the target bending angle is achieved.

[0049] The following describes the bending process method of this embodiment, namely the bending operation performed by the bending machine 1.

[0050] Figure 2 This diagram illustrates the first step of the bending process performed by the bending machine. At the start of the bending operation, the upper worktable 7 is at its top dead center (Ht), and its tilt is set to be horizontal. The left and right hydraulic cylinders 9L and 9R allow the upper worktable 7 to move vertically (Z) within the range from the top dead center (Ht) to the bottom dead center (Hb). The top dead center (Ht) is the point where the upper worktable 7 is a predetermined distance away from the lower worktable 5, and the bottom dead center (Hb) is the point where the upper worktable 7 is closest to the lower worktable 5.

[0051] like Figure 2 As shown, the control device 30 moves the upper worktable 7 downward while maintaining a horizontal tilt.

[0052] Figure 3This is an explanatory diagram illustrating the second step of the bending process performed by the bending machine. When the upper worktable 7 reaches the reference position H1, the control device 30 sets the upper worktable 7 to a tilted state to the lower left. As a method to switch the upper worktable 7 to the tilted state to the lower left, for example, the left hydraulic cylinder 9L is lowered and the right hydraulic cylinder 9R is raised.

[0053] From the perspective of setting the tilt state of the upper worktable 7 before it reaches the lower dead center Hb, the reference position H1 is set at a position higher than the lower dead center Hb. Examples of reference positions H1 include: (1) the speed switching position for switching the descent speed of the upper worktable 7; (2) the position where the front end of the upper die 8 abuts against the workpiece W (the so-called pin point); and (3) the position where pressure is applied to the workpiece W between the upper die 8 and the lower die 6, causing the workpiece W to bend at a predetermined reference angle. The reference angle is the angle used to determine if the workpiece W has bent by a predetermined amount, and is set to an angle larger than the target bending angle.

[0054] Figure 4 This is an explanatory diagram illustrating the third step of the bending process performed by the bending machine. The control device 30 lowers the upper worktable 7 while maintaining a downward and leftward tilt, applying pressure to the workpiece W between the upper worktable 7 and the lower worktable 5. Since the upper worktable 7 is set to a downward and leftward tilt, the left side of the upper die 8 contacts the left side of the workpiece W first. Furthermore, the central and right sides of the upper die 8 separate from the central and right sides of the workpiece W. Therefore, only the limited pressure range on the left side of the workpiece W (hereinafter referred to as the "left pressure range") La is locally pressured. This left pressure range La is narrower than the pressure range (the bending range of the workpiece W in the left-right direction X) applied using the entire area of ​​the upper die 8 and the lower die 6 in the left-right direction X. For example, the left pressure range La is approximately 1 / 3 of the length (the total length of the bending line) of the entire area of ​​the workpiece W in the left-right direction X.

[0055] Figure 5This is an explanatory diagram illustrating the fourth step of the bending process performed by the bending machine. Because the upper worktable 7 is tilted downwards and to the left, the left region of the left pressure range La has a larger bending angle than the right region. Therefore, in order to eliminate the deviation in bending angle within the left pressure range La, the control device 30 sets the bending state of the lower worktable 5 along the tilt of the upper worktable 7. Specifically, the control device 30 sets the bending state of the lower worktable 5 such that the left side of the lower worktable 5 is tilted downwards and to the left along the upper worktable 7. For example, the control device 30 bends the portion of the lower worktable 5 that is further to the left of the center upwards into a convex shape. However, the bending state of the lower worktable 5 is not limited to the tilt of the left side of the lower worktable 5 along the downwards and to the left of the upper worktable 7. The control device 30 controls one or both of the left and right eccentric shaft units 19L and 19R to set the bending state of the lower worktable 5.

[0056] Furthermore, in this embodiment, the control device 30 sets the bending state of the lower worktable 5 after the upper worktable 7 applies pressure to the workpiece W. However, the control device 30 may also set the bending state of the lower worktable 5 before the upper worktable 7 applies pressure to the workpiece W. However, if the bending state of the lower worktable 5 is set in advance, the workpiece W may shift due to the bending of the lower worktable 5. Therefore, it is preferable to set the bending state of the lower worktable 5 while the upper worktable 7 is applying pressure to the workpiece W and fixing the workpiece W in place.

[0057] Figure 6 This is an explanatory diagram illustrating the fifth step of the bending process performed by the bending machine. If the upper worktable 7 continues to descend until it reaches the lower stop point Hb, not only the left side of the workpiece W, but also the entire area of ​​the workpiece W in the left-right direction X is pressurized. Therefore, the control device 30 raises the upper worktable 7 before the entire area of ​​the workpiece W in the left-right direction X is pressurized, that is, before the upper worktable 7 reaches the lower stop point Hb. This relieves the pressure acting on the workpiece W.

[0058] The control device 30, in conjunction with depressurization, removes the bending state of the lower worktable 5 and adjusts it so that the entire area of ​​the lower worktable 5 in the left-right direction X is flat.

[0059] When the upper worktable 7 is raised during depressurization, if the upper worktable 7 is raised too much, the workpiece W may shift. Therefore, the control device 30 preferably raises the upper worktable 7 to the position where the springback of the workpiece W ends. By raising the upper worktable 7 within this range, the workpiece W can be kept in contact with the upper die 8, thus suppressing the positional shift of the workpiece W.

[0060] The position where the springback of workpiece W ends refers to the position where the pressure on workpiece W is gradually released by raising the upper worktable 7, and the pressure is approximately 0. The position where the springback ends can be determined based on (1) known information calculated based on the processing conditions, (2) the pressure values ​​of the left and right hydraulic cylinders 9L and 9R, and (3) the measured value of the bending angle of workpiece W obtained by angle sensors, etc.

[0061] Furthermore, when the control device 30 raises the upper worktable 7, it rises parallel to the upper worktable 7 while maintaining its tilted state during pressurization, i.e., its tilted state to the lower left. By rising parallel to the upper worktable 7 while maintaining its tilted state, the load acting on the left-side pressurization range La can be released evenly. Therefore, the uniformity accuracy within the left-side pressurization range La can be improved.

[0062] Figure 7 This is an explanatory diagram showing the sixth step of the bending process performed by the bending machine. When the pressurization and depressurization of the left-hand pressure range La are completed, the control device 30 sets the upper worktable 7 to a horizontal tilt state. As a method of switching from the downward left tilt state to the horizontal tilt state, for example, the left hydraulic cylinder 9L is raised and the right hydraulic cylinder 9R is lowered.

[0063] Figure 8 This is an explanatory diagram showing the seventh step of the bending process performed by the bending machine. The control device 30 lowers the upper worktable 7 while maintaining a horizontal tilt, and applies pressure to the workpiece W between the upper worktable 7 and the lower worktable 5.

[0064] Figure 9 This is an explanatory diagram illustrating the eighth step of the bending process performed by the bending machine. If pressure is applied to the workpiece W with only the upper worktable 7 lowered, the entire area of ​​the workpiece W in the left-right direction X is pressurized. Therefore, the control device 30 sets the bending state of the lower worktable 5 so that, together with the pressurization of the upper worktable 7, localized pressure is applied to a defined pressure range (hereinafter referred to as the "central pressure range") Lb located at the center of the workpiece W. Specifically, the control device 30 sets the bending state of the lower worktable 5 such that the center of the lower worktable 5 bends upward into a convex shape. The control device 30 controls one or both of the left and right eccentric shaft units 19L and 19R to set the bending state of the lower worktable 5.

[0065] The upper worktable 7 is set to a horizontally inclined state, but the center of the lower worktable 5 is curved upwards. Therefore, the central area of ​​the upper die 8 first contacts the central area of ​​the workpiece W. Furthermore, the left and right sides of the upper die 8 are separated from the left and right sides of the workpiece W. Therefore, only the central pressure range Lb is locally pressured. This central pressure range Lb is narrower than the pressure range (the bending range of the workpiece W in the left-right direction X) used to pressure the workpiece W using the entire area of ​​the upper die 8 and the lower die 6 in the left-right direction X. For example, the defined pressure range Lb is approximately 1 / 3 of the length (the full length of the bending line) of the entire area of ​​the workpiece W in the left-right direction X.

[0066] In addition, in order to eliminate the deviation of the bending angle in the central pressure range Lb, the control device 30 sets the bending state of the lower worktable 5 in a manner that follows the inclined state of the upper worktable 7, for example, with a trapezoidal shape with a flat bottom.

[0067] Figure 10 This is an explanatory diagram showing the ninth step of the bending process performed by the bending machine. If the upper worktable 7 continues to descend until it reaches the lower dead center Hb, pressure is applied not only to the center of the workpiece W but also to the entire area of ​​the workpiece W in the left-right direction X. Therefore, the control device 30 raises the upper worktable 7 before the entire area of ​​the workpiece W in the left-right direction X is pressured, that is, before the upper worktable 7 reaches the lower dead center Hb. This relieves the pressure acting on the workpiece W. The method of raising the upper worktable 7 to relieve pressure is as described above.

[0068] The control device 30, in conjunction with depressurization, removes the bending state of the lower worktable 5 and adjusts it so that the entire area of ​​the lower worktable 5 in the left-right direction X is flat.

[0069] Figure 11 This is an explanatory diagram showing the tenth step of the bending process performed by the bending machine. The control device 30 sets the upper worktable 7 to a downward and rightward tilt. As a method to set the upper worktable 7 to the downward and rightward tilt, for example, the right hydraulic cylinder 9R is lowered and the left hydraulic cylinder 9L is raised.

[0070] Figure 12This is an explanatory diagram illustrating the eleventh bending operation performed by the bending machine. The control device 30 lowers the upper worktable 7 while maintaining a downward and rightward tilt, applying pressure to the workpiece W between the upper worktable 7 and the lower worktable 5. Since the upper worktable 7 is set to a downward and rightward tilt, the right side of the upper die 8 contacts the right side of the workpiece W first. Furthermore, the left and central areas of the upper die 8 separate from the left and central areas of the workpiece W. Therefore, only the defined pressure range on the right side of the workpiece W (hereinafter referred to as the "right-side pressure range") Lc is locally pressured. This right-side pressure range Lc is narrower than the pressure range (the bending range of the workpiece W in the left-right direction X) applied using the entire area of ​​the upper die 8 and lower die 6 in the left-right direction X. For example, the right-side pressure range Lc is approximately 1 / 3 of the length (the total length of the bending line) of the entire area of ​​the workpiece W in the left-right direction X.

[0071] Furthermore, in order to eliminate the deviation of the bending angle within the right-side pressure range Lc, the control device 30 sets the bending state of the lower worktable 5 in a manner that follows the tilt of the upper worktable 7. Specifically, the control device 30 sets the bending state of the lower worktable 5 such that the right side of the lower worktable 5 corresponding to the defined pressure range Lc tilts downward to the right along the upper worktable 7. For example, the control device 30 bends the portion of the lower worktable 5 to the right of the center upward into a convex shape. However, it is not limited to the right side of the lower worktable 5 tilting downward to the right along the upper worktable 7. The control device 30 controls one or both of the left and right eccentric shaft units 19L and 19R to set the bending state of the lower worktable 5.

[0072] In this way, the control device 30 switches between the tilt state of the upper worktable 7 and the bending state of the lower worktable 5, repeatedly applying pressure (partial bending) to the three pressure ranges La, Lb, and Lc. As a result, the control device 30 performs full-area bending by applying pressure to the entire region of the workpiece W in the left-right direction X.

[0073] The control device 30 repeatedly bends the entire area multiple times, bending the workpiece W in stages until the target bending angle is reached. Then, when the workpiece W is bent to the target bending angle, the bending process on the workpiece W ends.

[0074] Next, refer to Figure 13 as well as Figure 14 The method for determining the output of the left and right hydraulic cylinders 9L and 9R when pressurizing each pressurization range La, Lb, and Lc, as well as the output of the left and right eccentric shaft units 19L and 19R, is explained. Figure 13 This is an explanatory diagram showing the angle measurement points of the workpiece. Figure 14This is a diagram showing the input screen for the angle measurement results.

[0075] The outputs of the left and right hydraulic cylinders 9L and 9R are control parameters corresponding to the pressing amount and tilting amount of the upper worktable 7. The pressing amount of the upper worktable 7 refers to the amount of descent of the upper worktable 7 required to obtain a predetermined bending angle from the pin point. The outputs of the left and right eccentric shaft units 19L and 19R are control parameters corresponding to the bending position, bending shape, and bending size of the lower worktable 5.

[0076] First, based on the bending conditions of the workpiece W, namely the plate thickness, material, and length of the bending line, the control device 30 temporarily determines the output of the left and right hydraulic cylinders 9L and 9R and the output of the left and right eccentric shaft units 19L and 19R for each pressure range La, Lb, and Lc.

[0077] The operator prepares workpiece W for trial bending. Under the control of the control device 30, for each pressure range La, Lb, Lc, the operator switches between the tilt state of the upper worktable 7 and the bending state of the lower worktable 5, repeatedly applying pressure (partial bending) to each pressure range La, Lb, Lc. Thus, pressure is applied to the entire area of ​​the workpiece W in the left-right direction X (the entire area of ​​the bending line) (the entire area is bent).

[0078] Then, as Figure 13 As shown, the bending angle of workpiece W is measured at various angle measurement points M1 to M4. Specifically, angle measurement point M1 is the left end of workpiece W, i.e., the left end of the left-side pressure range La. Angle measurement point M2 is the right end of the left-side pressure range La and the left end of the central pressure range Lb. Angle measurement point M3 is the right end of the central pressure range Lb and the left end of the left-side pressure range Lc. Angle measurement point M4 is the right end of workpiece W, i.e., the right end of the right-side pressure range Lc. Thus, the four angle measurement points M1 to M4 are located at the boundaries of each pressure range La, Lb, and Lc.

[0079] The bending angles at each angle measurement point M1 to M4 can be measured manually by the operator using an angle sensor. Alternatively, the operator can measure the bending angles using the control panel 35 (see reference). Figure 14 The control device 30 performs a predetermined operation, causing the angle sensor mounted on the bending machine 1 to activate and automatically measure the bending angle at each angle measurement point M1 to M4.

[0080] When the operator manually measures the bending angle, the control device 30 can obtain this information by inputting the measured values ​​of the bending angle at each angle measurement point M1 to M4 into the operation panel. Alternatively, when the control device 30 automatically measures the bending angle, it can directly obtain the measured values ​​of the bending angle at each angle measurement point M1 to M4 from the angle sensor.

[0081] Thus, the bending angles measured at each angle measurement point M1 to M4 are input to the control device 30. For example... Figure 14 As shown, the control device 30 displays the measured values ​​of the bending angles at each angle measurement point M1 to M4 on a predetermined display screen 36 of the operation panel 35. This display screen 36 includes four display items 36a to 36d for displaying the measured values ​​of the bending angles at each angle measurement point M1 to M4.

[0082] Based on the bending angles measured at each angle measurement point M1 to M4, the control device 30 performs necessary calculations for each of the three pressurization ranges La, Lb, and Lc.

[0083] Specifically, the control device 30 uses the bending angles obtained from three angle measurement points M1 to M3 to correct the outputs of the left and right hydraulic cylinders 9L and 9R, as well as the outputs of the left and right eccentric shaft units 19L and 19R, when pressurizing the left-side pressurization range La. At this time, the control device 30 corrects the outputs of the left and right hydraulic cylinders 9L and 9R based on angle measurement points M1 and M3, and corrects the outputs of the left and right eccentric shaft units 19L and 19R based on angle measurement point M2.

[0084] Similarly, the control device 30 uses the bending angles obtained from four angle measurement points M1 to M4 to correct the outputs of the left and right hydraulic cylinders 9L and 9R, as well as the outputs of the left and right eccentric shaft units 19L and 19R, when pressurizing the central pressurization range Lb. At this time, the control device 30 corrects the output of the left hydraulic cylinder 9L based on angle measurement point M1, and corrects the output of the right hydraulic cylinder 9R based on angle measurement point M4. The control device 30 corrects the output of the left eccentric shaft unit 19L based on angle measurement point M2, and corrects the output of the right eccentric shaft unit 19R based on angle measurement point M3.

[0085] Furthermore, the control device 30 uses three bending angles at angle measuring points M2 to M4 to correct the outputs of the left and right hydraulic cylinders 9L and 9R, as well as the outputs of the left and right eccentric shaft units 19L and 19R, when pressurizing the right-side pressurization range Lc. At this time, the control device 30 corrects the outputs of the left and right hydraulic cylinders 9L and 9R based on angle measuring points M2 and M4, and corrects the outputs of the left and right eccentric shaft units 19L and 19R based on angle measuring point M3.

[0086] If this correction is implemented, the control device 30 controls the left and right hydraulic cylinders 9L and 9R, as well as the left and right eccentric shaft units 19L and 19R, according to the corrected output. This allows pressure to be applied to the workpiece W at an appropriate output.

[0087] Furthermore, in the above description, before the angle measurement, for the workpiece W used for trial bending, pressure is repeatedly applied to three pressure ranges La, Lb, and Lc (partial bending), thereby applying pressure to the entire area of ​​the workpiece W in the left-right direction X (bending of the entire area). However, it is also possible to apply pressure to the entire area of ​​the workpiece W at once while the upper worktable 7 is kept in a horizontally tilted state, and measure the bending angle of the workpiece W at this time.

[0088] As explained above, in the bending machine 1 of this embodiment, the control device 30 sets the tilt state of the upper worktable 7 and sets the bending state of the lower worktable 5 along the tilt state of the upper worktable 7, performing local bending by applying pressure within a limited pressure range La, Lb, Lc, which is defined as the pressure range for applying pressure to the workpiece W in the left-right direction X of the upper die 8 and the lower die 6. Furthermore, the control device 30 switches the combination of the tilt state of the upper worktable 7 and the bending state of the lower worktable 5, and repeatedly performs local bending while shifting the limited pressure range La, Lb, Lc, thereby performing full-area bending by applying pressure to the workpiece W in the left-right direction X.

[0089] According to the bending machine 1 of this embodiment, the following first effect is achieved. That is, according to the bending machine 1 of this embodiment, pressure is not applied to the entire area of ​​the workpiece W (the bending line of the workpiece W) at once, but to a defined pressure range La, Lb, Lc. At this time, the upper worktable 7 is tilted according to the pressure range La, Lb, Lc, and the lower worktable 5 is bent along this tilted state, thereby suppressing the deflection of the worktable within the pressure range La, Lb, Lc. Since the deflection of the worktable within the pressure range La, Lb, Lc is suppressed, the distance between the lower end of the upper die 8 and the upper end of the lower die 6 during pressure application can be kept constant. As a result, the bending angle is made consistent throughout the entire area of ​​the pressure range La, Lb, Lc that is pressured by the upper die 8 and the lower die 6, thus improving the uniformity accuracy within the pressure range La, Lb, Lc.

[0090] For example, even when switching the tilt state of the upper worktable 7 for each pressure range La, Lb, Lc, if the bending state of the lower worktable 5 is fixed, there is a possibility that the bending state of the lower worktable 5 is inconsistent with the tilt state of the upper worktable 7. Similarly, even when switching the bending state of the lower worktable 5 for each pressure range La, Lb, Lc, if the tilt state of the upper worktable 7 is fixed, there is a possibility that the bending state of the lower worktable 5 is inconsistent with the tilt state of the upper worktable 7. In this case, the distance between the lower end of the upper mold 8 and the upper end of the lower mold 6 deviates. Therefore, as shown in this embodiment, it is important to set the tilt state of the upper worktable and the bending state of the lower worktable 5 along the tilt state according to the pressure ranges La, Lb, Lc.

[0091] Furthermore, by repeatedly performing localized bending to shift the pressure ranges La, Lb, and Lc, pressure can be applied to the workpiece W across the entire region in the left-right direction X. Since the bending angle is maintained within each pressure range La, Lb, and Lc where localized bending occurs, bending across the entire region ensures consistent bending angles throughout the left-right direction X of the workpiece W. Therefore, sufficient uniformity accuracy can be achieved across the entire region in the left-right direction X of the workpiece W.

[0092] Furthermore, the bending machine 1 according to this embodiment also achieves the following second effect. First, consider a bending method in which the upper worktable 7 is lowered in a horizontally inclined state, and pressure is applied to the workpiece W in the entire area of ​​the left-right direction X using the upper die 8 and the lower die 6. In this bending method, pressure is applied to the entire area of ​​the workpiece W in the left-right direction X by bearing the bending load from the upper worktable 7. Figure 4 The area corresponding to the left-hand pressure range La shown receives approximately one-third of the load acting from the upper worktable 7. In contrast, as shown in this embodiment, when only the left-hand pressure range La is locally pressurized, the load acting from the upper worktable 7 is concentrated on the left-hand pressure range La. Therefore, by limiting pressurization to the left-hand pressure range La, even a bending load smaller than that required to pressurize the entire area of ​​the workpiece W in the left-right direction X can exert the same pressure on the workpiece W. In other words, by pressurizing the left-hand pressure range La, the bending machine 1 can perform bending processing with a bending load smaller than that required to pressurize the entire area of ​​the workpiece W in the left-right direction X.

[0093] Similarly, as Figure 9As shown, the bending machine 1 applies pressure through a centrally defined pressure range Lb, enabling bending operations with a smaller bending load than that required when applying pressure to the entire area of ​​the workpiece W in the left-right direction X. Furthermore, as... Figure 12 As shown, the bending machine 1 applies pressure by limiting the pressure range Lc to the right, and can perform bending processing with a bending load that is smaller than the bending load required when applying pressure to the entire area of ​​the workpiece W in the left-right direction X.

[0094] In this way, by utilizing the tilted state of the upper worktable 7 and the bent state of the lower worktable 5, localized pressure can be applied to a defined pressure range. In this case, the bending load acting from the upper worktable 7 is concentrated on the defined pressure ranges La, Lb, and Lc. By applying pressure to the defined pressure ranges La, Lb, and Lc, even a bending load smaller than that required to apply pressure to the entire area of ​​the workpiece W in the left-right direction X can exert the same pressure (stress) on the pressure range. That is, by applying pressure to the defined pressure ranges La, Lb, and Lc, the bending machine 1 can perform bending processing with a bending load smaller than that required to apply pressure to the entire area of ​​the workpiece W in the left-right direction X. Therefore, the desired bending processing of the workpiece W can be performed without using a bending machine 1 with a high pressure capacity.

[0095] Furthermore, as described above, by switching the combination of the tilt state of the upper worktable 7 and the bending state of the lower worktable 5, the defined pressure ranges La, Lb, and Lc can be shifted. Thus, without using a bending machine 1 with high pressure capacity, it is possible to appropriately apply pressure to the entire area of ​​the workpiece W in the left-right direction X.

[0096] In the bending machine 1 of this embodiment, the control device 30 repeatedly bends the entire area multiple times, bending the workpiece W in stages to the target bending angle.

[0097] According to this structure, by bending the workpiece W in stages, the bending angle of the workpiece W can be gradually approached to the target bending angle. This allows for a more reliable improvement in uniformity accuracy. Furthermore, even with small bending loads, the workpiece W can be bent to the target bending angle by bending it in stages. Therefore, the workpiece W can be bent to the desired target bending angle without using a bending machine 1 with high pressure capacity.

[0098] In the bending machine 1 of this embodiment, the left and right hydraulic cylinders 9L and 9R can move the upper worktable 7 within the range from the upper dead point Ht to the lower dead point Hb. When performing partial bending, the control device 30 sets the tilt state of the upper worktable 7 before the upper worktable 7 reaches the lower dead point Hb.

[0099] When pressure is applied to the entire area of ​​the workpiece W in the left-right direction X, the bending load is distributed across the entire area of ​​the workpiece W, thus preventing the pressure required for bending from being applied to the workpiece W. Regarding this, according to the structure of this embodiment, the upper worktable 7 is tilted before reaching the lower stop point Hb, thereby preventing the entire area of ​​the workpiece W in the left-right direction X from being pressurized at once. Since pressure can be applied to the workpiece W within each pressure range La, Lb, Lc, the uniformity accuracy can be improved through each pressure range La, Lb, Lc. Furthermore, without using a bending machine 1 with high pressure capacity, the desired bending process can be performed within each pressure range La, Lb, Lc.

[0100] In the bending machine 1 of this embodiment, after the control device 30 applies pressure to the workpiece W, it moves the upper worktable 7 to the upper stop point Ht side by means of the springback of the workpiece W within the range of contact between the upper die 8 and the workpiece W, and then switches the combination of the tilt state of the upper worktable 7 and the bending state of the lower worktable 5.

[0101] According to this structure, even when the upper worktable 7 rises during depressurization, it only rises within the range where the upper die 8 contacts the workpiece W. Therefore, when switching between the tilted state of the upper worktable 7 and the bent state of the fixed worktable, the upper die 8 presses down on the workpiece W, thereby suppressing positional displacement of the workpiece W. This allows for high-precision bending of the workpiece W. Uniformity accuracy can be improved through the various pressure ranges La, Lb, and Lc.

[0102] In the bending machine 1 of this embodiment, the control device 30 moves the upper worktable 7 to the upper dead point Ht side while maintaining the tilted state when applying pressure to the workpiece W.

[0103] According to this structure, since the upper worktable 7 is moved while maintaining its tilted state, the load acting on the pressure range can be released evenly. This improves the uniformity accuracy of the workpiece W within each pressure range La, Lb, and Lc.

[0104] In the bending machine 1 of this embodiment, the control device 30 bends the left side of the lower worktable 5 upward when the left side of the upper worktable 7 is closer to the lower worktable 5 than the right side.

[0105] According to this structure, pressure can be applied to the left side region of the workpiece W with high uniformity accuracy.

[0106] In the bending machine 1 of this embodiment, when the control device 30 is in an inclined state where the right side of the upper worktable 7 is closer to the lower worktable 5 than the left side, the right side of the lower worktable 5 is bent upward.

[0107] According to this structure, pressure can be applied to the right side region of workpiece W with high uniformity accuracy.

[0108] In the bending machine 1 of this embodiment, the control device 30 bends the center of the lower worktable 5 upwards when the upper worktable 7 is tilted so that the left and right sides are horizontal.

[0109] According to this structure, pressure can be applied to the central region of the workpiece W with high uniformity and accuracy.

[0110] In this embodiment, the lifting mechanism consists of left and right hydraulic cylinders (an example of a lifting unit) 9L and 9R, which are disposed at the left and right ends of the movable worktable and can be controlled independently of each other. The convex surface machining mechanism consists of left and right eccentric shaft units (an example of a convex surface machining unit) 19L and 19R, which are symmetrically arranged with reference to the center position of the lower worktable 5 in the left-right direction X and can be controlled independently of each other.

[0111] Based on this structure, by independently controlling the left and right eccentric shaft units 19L and 19R, the bending shape of the lower worktable 5 can be made symmetrical or asymmetrical. Therefore, the bending state of the lower worktable 5 can be appropriately controlled along the tilt of the upper worktable 7.

[0112] In addition, in this embodiment, the control device 30 corrects the outputs of the left and right hydraulic cylinders 9L and 9R and the outputs of the left and right eccentric shaft units 19L and 19R based on the bending angles obtained from four angle measurement points M1 to M4 at the boundaries of the pressurization ranges La, Lb and Lc located on the left, center and right sides.

[0113] For example, consider measuring angles at three points on the left, center, and right of workpiece W, and then correcting the outputs of hydraulic cylinders 9L and 9R, as well as the outputs of the left and right eccentric shaft units 19L and 19R. When correcting based on the left-side pressure range La, the outputs of the left and right hydraulic cylinders 9L and 9R are corrected based on the two points on the left and center, while the outputs of the left and right eccentric shaft units 19L and 19R are corrected based on the center point. In this case, the bending angle obtained at the same point (the center point) is used in both the output corrections of hydraulic cylinders 9L and 9R and the output corrections of the left and right eccentric shaft units 19L and 19R. Therefore, it is difficult to distinguish which output is corrected to what extent, sometimes resulting in multiple solutions.

[0114] Regarding this point, according to the structure of this embodiment, in the output correction of the left and right hydraulic cylinders 9L and 9R and the output correction of the left and right eccentric shaft units 19L and 19R, the bending angle obtained from different angle measurement points M1 to M4 can be utilized. For example, when correcting the pressure range La on the left side, the output of the left and right hydraulic cylinders 9L and 9R is corrected based on angle measurement points M1 and M3, and the output of the left and right eccentric shaft units 19L and 19R is corrected based on angle measurement point M2, which is different from both angle measurement points M1 and M3. In this way, different angle measurement points can be assigned to the output correction of the hydraulic cylinders 9L and 9R and the output correction of the left and right eccentric shaft units 19L and 19R, so the output correction value is uniquely determined. Therefore, appropriate correction can be performed.

[0115] Furthermore, in the above-described embodiment, a bending machine 1 is illustrated, comprising an upper worktable 7, which is equivalent to a movable worktable, and a lower worktable 5, which is equivalent to a fixed worktable. However, the bending machine may also have a structure comprising a lower worktable, which is equivalent to a movable worktable, and an upper worktable, which is equivalent to a fixed worktable.

[0116] Furthermore, in the above-described embodiment, the bending machine is a structure that bends the fixed worktable by tilting the movable worktable that moves in the vertical direction Z. However, the bending machine may also be a structure that bends the movable worktable that moves in the vertical direction Z and tilts the fixed worktable.

[0117] Furthermore, the bending processing method of this embodiment sets the tilt state of the movable worktable and sets the bending state of the fixed worktable in a manner that follows the tilt state of the movable worktable. It performs local bending of the workpiece by applying pressure to a limited pressure range that is greater than the pressure range when the workpiece W is pressured in the entire area of ​​the left-right direction X using the first mold and the second mold. By switching the combination of the tilt state of the movable worktable and the bending state of the fixed worktable, local bending is repeatedly performed while shifting the limited pressure range, thereby performing full-area bending of the workpiece by applying pressure to the entire area in the left-right direction.

[0118] Thus, in addition to the bending machine 1 shown in this embodiment, the bending method for bending workpiece W using the bending machine 1 also functions as part of this invention. Furthermore, this bending method achieves the same effects as the bending machine 1 described above.

[0119] Furthermore, in this embodiment, the pressure range is shifted in the order of left side, center, and right side of workpiece W. However, the method of shifting the pressure range can be any of the following: (1) left side, right side, and center of workpiece W; (2) right side, center, and left side of workpiece W; (3) right side, left side, and center of workpiece W; (4) center, left side, and center of workpiece W; (5) center, right side, and left side of workpiece W.

[0120] Furthermore, in this embodiment, local bending is performed on three pressure zones formed by the left, center, and right sides of the workpiece W. However, the local bending can be performed within a pressure zone that is limited to the entire area of ​​the workpiece W pressured in the left-right direction X using the upper die 8 and the lower die 6. For example, local bending can also be performed on two pressure zones formed by the left and right halves of the workpiece W. Alternatively, the left, center, and right regions of the workpiece W can be further subdivided, and local bending can be performed within each subdivided pressure zone.

[0121] Figure 15 This is an explanatory diagram showing an example of a workpiece that is to be processed. In the above embodiment, the workpiece to be processed is a workpiece W having a continuous curved line in the left-right direction. However, the workpiece to be processed may also be a workpiece W1, in which the curved lines Ba and Bc are deflected to the left and right by providing a cutout C.

[0122] Figure 16 and Figure 17 This diagram illustrates the action of alternately applying pressure to the workpiece from left to right. Even for a workpiece W1 like this, the bending process is performed in the same way as described above within each pressure range La1, Lc1 corresponding to each bending line Ba, Bc. Specifically, the control device 30 controls the upper worktable 7 to tilt downwards to the left, and controls the bending state of the left side of the lower worktable 5 along this downward-left tilt. In this state, pressure is applied to the pressure range La1 corresponding to the bending line Ba. Similarly, the control device 30 controls the upper worktable 7 to tilt downwards to the right, and controls the bending state of the right side of the lower worktable 5 along this downward-right tilt. In this state, pressure is applied to the pressure range Lc1 corresponding to the bending line Bc.

[0123] In a workpiece W1 with left-right biased curvatures Ba and Bc, if the upper worktable 7 is lowered while in a horizontally inclined state, the pressure reaction force at the cut section C does not act on the upper worktable 7 and the lower worktable 5. Due to the uneven pressure reaction force acting on the upper and lower worktables 7 and 5, unnecessary deflection occurs, and uniformity cannot be ensured along their respective curvatures Ba and Bc. Regarding this, according to this embodiment, regardless of the pressure range La1 or Lc1, deviations in the bending angle can be suppressed within this pressure range. As a result, uniformity can be improved within each pressure range La1 or Lc1. Therefore, sufficient uniformity can be obtained throughout the entire region of the workpiece W in the left-right direction X, i.e., the entire region of the left-right biased curvatures.

[0124] In this embodiment, during depressurization, the movable worktable is moved in the vertical direction Z while maintaining its tilted state. However, the control device 30 may also, after the pressurization action for a certain pressurization range is completed, not raise the movable worktable, but directly switch the movable worktable to the tilted state corresponding to the next pressurization range.

[0125] In this embodiment, a mechanism for bending a portion of a worktable on which a mold is mounted is exemplified as a convex surface machining mechanism. However, it is also possible to pre-form a curved shape using a mold or the like mounted on the worktable without bending the worktable itself. In this specification, in addition to methods that bend the worktable itself, structures that can achieve the same effect as bending the worktable using an object attached to the worktable are also explained as convex surface machining mechanisms.

[0126] As described above, embodiments of the present invention have been presented, but should not be construed as limiting the invention by the descriptions and drawings that form part of this disclosure. Based on this disclosure, those skilled in the art will understand various alternative embodiments, examples, and techniques employed.

[0127] Symbol Explanation

[0128] The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2021-130572 filed on August 10, 2021, and Japanese Patent Application No. 2022-125542 filed on August 5, 2022, the entire contents of which are incorporated herein by reference.

Claims

1. A bending machine comprising: a movable worktable on which a first mold is mounted in a left-right direction; and a fixed worktable disposed opposite the movable worktable in a vertical direction, on which a second mold is mounted in a left-right direction. The workpiece is bent by applying pressure between the first mold and the second mold by moving the movable worktable in the vertical direction. The bending machine is characterized by having: The lifting mechanism allows the movable worktable to move vertically and freely adjusts its left and right tilt, i.e., its tilt state. A convex surface machining mechanism that bends a portion of the fixed worktable; and A control device that controls the lifting mechanism and the convex surface processing mechanism. The control device sets the tilt state of the movable worktable and sets the bending state of the fixed worktable in a manner that follows the tilt state of the movable worktable, performing localized bending by applying pressure to a limited area that is greater than the pressure range used to apply pressure to the workpiece in the left-right direction of the entire area using the first mold and the second mold. The control device applies pressure to the defined pressure range by switching between the tilt state of the movable worktable and the bending state of the fixed worktable to perform the local bending. While shifting the defined pressure range, the local bending is repeatedly performed, thereby performing full-area bending that applies pressure to the workpiece in the entire left-right direction.

2. The bending machine according to claim 1, characterized in that, The control device repeatedly bends the entire area multiple times, bending the workpiece in stages to the target bending angle.

3. The bending machine according to claim 1 or 2, characterized in that, The lifting mechanism enables the movable worktable to move within a range from its upper stop point, which is a predetermined distance away from the fixed worktable, to its lower stop point, which is closest to the fixed worktable. In the case of the aforementioned local bending, the control device sets the tilt state of the movable worktable before the movable worktable reaches the lower stop point.

4. The bending machine according to claim 3, characterized in that, After the partial bending is performed, the control device moves the movable worktable toward the upper stop point by means of the springback of the workpiece within the range of contact between the first mold and the workpiece, and then switches the combination of the tilt state of the movable worktable and the bending state of the fixed worktable.

5. The bending machine according to claim 4, characterized in that, The control device moves the movable worktable toward the upper stop point while maintaining the tilted state of the workpiece when applying pressure within the defined pressure range.

6. The bending machine according to claim 1 or 2, characterized in that, When the movable worktable is in an inclined state where its left side is closer to the fixed worktable than its right side, the control device causes the left side of the fixed worktable to bend upward.

7. The bending machine according to claim 1 or 2, characterized in that, When the movable worktable is tilted, with its right side closer to the fixed worktable than its left side, the control device causes the right side of the fixed worktable to bend upwards.

8. The bending machine according to claim 1 or 2, characterized in that, When the movable worktable is in an inclined state where its left and right sides are horizontal, the control device causes the center of the fixed worktable to bend upward.

9. The bending machine according to claim 1 or 2, characterized in that, The lifting mechanism consists of left and right lifting units located at the left and right ends of the movable worktable and capable of being controlled independently of each other. The convex surface processing mechanism consists of left and right convex surface processing units that are symmetrically arranged with the center position of the fixed worktable in the left and right directions as a reference and can be controlled independently.

10. The bending machine according to claim 9, characterized in that, When the workpiece is divided into three pressure zones—left, center, and right—for pressure application, The control device corrects the outputs of the left and right lifting units and the left and right convex surface processing units based on the bending angles obtained at four angle measurement points located at the boundaries of each pressurization range.

11. A bending machine comprising: a movable worktable on which a first mold is mounted in a left-right direction; and a fixed worktable disposed opposite the movable worktable in a vertical direction, on which a second mold is mounted in a left-right direction. The workpiece is bent by applying pressure between the first mold and the second mold by moving the movable worktable in the vertical direction. The bending machine is characterized by having: A lifting mechanism that allows the movable worktable to move in the vertical direction; The tilting mechanism can freely adjust the left and right tilt of the fixed worktable, i.e., the tilt state. A convex surface machining mechanism that bends a portion of the movable worktable; and A control device that controls the lifting mechanism, the tilting mechanism, and the convex surface processing mechanism. The control device sets the tilt state of the fixed worktable and sets the bending state of the movable worktable in a manner that follows the tilt state of the fixed worktable, performing localized bending by applying pressure to a range limited to the pressure range when the workpiece is pressured in the entire left-right direction area using the first mold and the second mold. The control device applies pressure to the defined pressure range by switching between the tilt state of the fixed worktable and the bending state of the movable worktable to perform the local bending. While shifting the defined pressure range, the local bending is repeatedly performed, thereby performing full-area bending that applies pressure to the workpiece in the entire left-right direction.

12. A bending process method, wherein a bending machine applies pressure to a workpiece between a first die and a second die by moving a movable worktable in a vertical direction, thereby bending the workpiece, the bending machine comprising: the movable worktable on which the first die is mounted in a horizontal direction; and a fixed worktable disposed opposite the movable worktable in a vertical direction, on which the second die is mounted in a horizontal direction. The bending process method is characterized by the following: Set the tilt state of the movable worktable; The bending state of the fixed worktable is set in a manner that follows the tilt state of the movable worktable. Local bending is performed by applying pressure to a limited area of ​​the workpiece, which is defined by the pressure range when pressure is applied to the entire area in the left-right direction using the first mold and the second mold; and By switching between the tilt state of the movable worktable and the bending state of the fixed worktable, the local bending is performed to apply pressure to the limited pressure range. While shifting the limited pressure range, the local bending is repeatedly performed, thereby performing full-area bending that applies pressure to the workpiece in the entire left-right direction.

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