Plate Bending Machine

Abstract

The plate bending machine (10) comprises: a lifting component (32) which is rotatably provided on each of a pair of support blocks (30) and extends in the vertical direction. A ball screw (36) is rotatably provided on the first lifting component (32), and a nut component (48) threadedly connected to the ball screw (36) is provided on the first support block (30). One end side of the extension part (56) in the left and right directions is connected to the upper end part of the first lifting component (32), and the other end side of the extension part (56) in the left and right directions is rotatably connected to the upper end part of the second lifting component (32). A support mechanism (62) is provided on the first lifting component (32) to support the extension part (56) from the bottom, and an abutment component (98) is provided on the extension part (56).

Description

Technical Field

[0001] The present invention relates to a plate bender for performing bending processing on a plate-shaped workpiece (metal plate) by cooperation between an upper die and a lower die. Background Art

[0002] The plate bending machine includes a reverse stroke stopper for positioning the workpiece in the front-rear direction relative to the lower die (see Patent Documents 1 to 3). The reverse stroke stopper has the following outline.

[0003] A pair of support blocks separated in the left-right direction are provided on the back side of the lower workbench of the main frame. The pair of support blocks are a first support block and a second support block. Each support block is provided with a lifting component extending in the vertical direction so that it can be raised and lowered. The pair of lifting components are a first lifting component and a second lifting component. Furthermore, an extension portion extending in the left-right direction is provided between the upper end of the first lifting component and the upper end of the second lifting component. One end of the extension portion in the left-right direction is fixed to the upper end of the first lifting component, and the other end of the extension portion in the left-right direction is fixed to the upper end of the second lifting component. Furthermore, a plurality of abutment components are provided on the extension portion, each of which has an abutment surface at its front end that can abut against the end face of a plate-shaped workpiece. Each abutment component is configured to be movable in the left-right direction and the front-back direction relative to the main frame. The abutment surface of each abutment component is positioned at a height corresponding to the height of the lower mold by the lifting and lowering action of the pair of lifting components.

[0004] Reverse stroke limiters are categorized into two types: a first type that drives a pair of lifting members by driving two motors (see Patent Documents 1 and 2), and a second type that drives a single motor (see Patent Document 3). Compared to the first type, the second type of reverse stroke limiter can reduce the number of motors and thus the cost of the plate bending machine. In the second type of reverse stroke limiter, the structure for raising and lowering the pair of lifting members is as follows.

[0005] Ball screws (threaded rods in Patent Document 3) extending vertically are provided downwardly at each end of the extending portion in the left and right directions. Nut components are provided on the upper ends of each lifting component (upper and lower guide pins in Patent Document 3) via other components (forward and backward moving beam components in Patent Document 3), and each nut component is threadedly engaged with each ball screw. A motor (a servo motor for vertical movement in Patent Document 3) is provided on the upper end of the first lifting component to rotate a pair of nuts. The output shaft of the motor is linked to the pair of nut components via a chain or timing belt.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-162558

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2019-130535

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 5-84520 Summary of the Invention

[0011] Furthermore, the second type of reverse stroke limiter includes a pair of ball screws and a pair of nut components. In other words, the second type of reverse stroke limiter includes two lifting ball screw mechanisms composed of the ball screws and nut components. Therefore, the second type of reverse stroke limiter requires adjustment to synchronize the two lifting ball screw mechanisms, resulting in a significant time and effort involved in adjusting the reverse stroke limiter.

[0012] A plate bender according to an embodiment of the present invention comprises: a pair of support blocks disposed on the back side of a lower table of a main frame and spaced apart in the left-right direction; a lifting member disposed on each of the pair of support blocks so as to be liftable and extending in the vertical direction; a ball screw rotatably disposed on a first lifting member of the pair of lifting members or a first supporting block of the pair of support blocks, extending in the vertical direction and rotated by a motor; and a nut member disposed on the first supporting block or the first lifting member and threadedly engaged with the ball screw. The plate bender according to this embodiment further comprises: an extension portion having one left-right end connected to the upper end of the first lifting member and the other left-right end connected to the upper end of the second lifting member of the pair of lifting members, extending in the left-right direction; an abutment member disposed on the extension portion, having an abutment surface capable of abutting the end face of a plate-shaped workpiece against the front end thereof, and configured to be movable in the forward and backward directions relative to the main frame; and a support mechanism disposed on the first lifting member and supporting the extension portion from below.

[0013] The pair of support blocks, the pair of lifting components, the extending portion, the supporting mechanism and the abutting component constitute a part of a reverse stroke limiting device for positioning the workpiece in the front-rear direction relative to the lower mold mounted on the lower workbench.

[0014] According to the above configuration, as described above, one end of the extending portion in the left-right direction is connected to the upper end of the first lifting member. The other end of the extending portion in the left-right direction is connected to the upper end of the second lifting member. The first lifting member is provided with the support mechanism that supports the extending portion from below. Therefore, by simply providing the reverse stroke limiter with a single lifting ball screw mechanism composed of the ball screw and the nut member, the pair of lifting members can be raised and lowered by driving a single motor. This reduces the cost of the plate bending machine while simplifying the adjustment of the reverse stroke limiter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic partial cross-sectional view of the plate bending machine of this embodiment.

[0016] Figure 2 It is a front view of the reverse stroke limiter according to this embodiment.

[0017] Figure 3 It is a top view of the reverse stroke limiter according to this embodiment.

[0018] Figure 4 It is a rear view of the reverse stroke limiter according to this embodiment.

[0019] Figure 5 It is along Figure 2 Figure 4 shows the VV line in Figure 4.

[0020] Figure 6 It is along Figure 2 Graph of the VI-VI line in .

[0021] Figure 7 yes Figure 2 An enlarged view of Section VII in FIG.

[0022] Figure 8 yes Figure 4 An enlarged view of Part VIII in FIG. DETAILED DESCRIPTION

[0023] Below, refer to Figures 1 to 8 This embodiment will be described.

[0024] In addition, within the scope of the specification and technical solutions of the present application, "setting" includes not only direct setting but also indirect setting via other components. "Left-right direction" is one of the horizontal directions, which is the width direction of the plate bender, also known as the Y-axis direction. "Inside of the left-right direction" refers to the center side of the width direction of the plate bender. "Front-back direction" is a horizontal direction orthogonal to the left-right direction, which is the depth direction of the plate bender, also known as the L-axis direction. In the accompanying drawings, "FF" refers to the front direction, "FR" refers to the rear direction, "L" refers to the left direction, "R" refers to the right direction, "U" refers to the upper direction, and "D" refers to the lower direction.

[0025] like Figure 1 As shown, the plate bender 10 of this embodiment is a machine that bends a plate-shaped workpiece (metal plate) W by cooperating with an upper die (punch die) 12 and a lower die (die die) 14. The plate bender 10 includes a main frame 16 having a pair of side plates 18 spaced apart and opposed in the left-right direction and a plurality of connecting members (not shown) that integrally connect the pair of side plates 18. The pair of side plates 18 are a first (left) side plate 18 and a second (right) side plate 18.

[0026] A lower workbench 20 extending in the left-right direction is provided at the lower portion of the front side (front side) of the main frame 16. A lower mold holder 22 for detachably holding the lower mold 14 is provided on the upper side of the lower workbench 20. In addition, an upper workbench 24 extending in the left-right direction is provided at the upper portion of the front side of the main frame 16 so as to be liftable (movable in the up-down direction). The upper workbench 24 is lifted and lowered by driving a lifting hydraulic cylinder (not shown) or a lifting motor (not shown) as a lifting actuator for a workbench provided at an appropriate position of the main frame 16. An upper mold holder 26 for detachably holding the upper mold 12 is provided on the lower side of the upper workbench 24. Instead of configuring the upper workbench 24 to be liftable, the lower workbench 20 may be configured to be liftable.

[0027] A reverse stroke stopper 28 is provided on the back side (rear) of the lower table 20 in the main frame 16 for positioning the workpiece W relative to the lower die 14 in the front-rear direction. Figure 1 In the schematic partial cross-sectional view of FIG, the reverse stroke limiter 28 provided on the left-right inner side of the second (right) side plate 18 is shown on the back side (rear) of the lower workbench 20. The specific structure of the reverse stroke limiter 28 is as follows.

[0028] like Figures 1 to 6As shown, a pair of support blocks (guide blocks) 30 are provided on the back side of the lower worktable 20 of the main frame 16, separated and opposed in the left-right direction. The pair of support blocks 30 are a first (left) and a second (right) support block 30. The first support block 30 is fixed to the first side plate 18, and the second support block 30 is fixed to the second side plate 18. Each support block 30 has a guide portion 30g extending in the vertical direction on its back side. Each support block 30 has a protrusion 30p protruding rearward on its left-right inner side. In addition, a lifting member 32 extending in the vertical direction is provided on the guide portion 30g of each support block 30 so as to be liftable via a slide rail 34. The pair of lifting members 32 are a first (left) and a second (right) lifting member 32. The first lifting member 32 has two protrusions 32p and 32b separated in the vertical direction on its back side. The second lifting member 32 has an extension portion 32e extending downward at its lower end. In addition, as an example, the drawings of the present application show a state in which the pair of lifting members 32 are located at the most descended position.

[0029] A ball screw 36 extending in the vertical direction is rotatably provided between the two protrusions 32p and 32b of the first lifting component 32. A lifting motor 38 for rotating the ball screw 36 is provided on the protrusion 32b of the first lifting component 32 via a bracket 40. The output shaft of the lifting motor 38 is linked to the ball screw 36 via two pulleys 42 and 44 and a timing belt 46. The ball screw 36 is raised and lowered while rotating by the drive of the lifting motor 38. In addition, a nut component 48 threadedly engaged with the ball screw 36 is provided on the protrusion 30p of the first support block 30. The reverse stroke limiter 28 includes a ball screw mechanism for lifting and lowering composed of the ball screw 36 and the nut component 48. In addition, instead of rotatably providing the ball screw 36 on the first lifting component 32, it can also be rotatably provided on the first support block 30. In this case, the nut member 48 is provided not on the first support block 30 but on the first lifting member 32 .

[0030] An electromagnetic brake 50 is provided on the protruding portion 32p of the first lifting member 32 to prevent the ball screw 36 from rotating. The electromagnetic brake 50 is configured to immobilize the ball screw 36 by applying a braking force when the plate bender 10 is powered off. While the electromagnetic brake 50 is separate from the lifting motor 38, the lifting motor 38 may also include an electromagnetic brake. The reverse stroke limiter 28 may also include another brake (not shown) to immobilize the ball screw 36 in place of the electromagnetic brake 50.

[0031] Between the protrusion 30p of the second support block 30 and the extension 32e of the second lift member 32, multiple tension springs 52 are provided in parallel as a balancer to reduce the weight acting on the second lift member 32. The multiple tension springs 52 act as biasing members to urge the second lift member 32 upward. The upper end of each tension spring 52 is secured to the protrusion 30p of the second support block 30 via a bracket 54, while the lower end of each tension spring 52 is secured to the lower end of the extension 32e of the second lift member 32.

[0032] like Figures 5 to 8 As shown, a square tubular extension 56 extending in the left-right direction is provided between the upper ends of the first and second lift members 32. The extension 56 has connecting portions 56j and 56c at one and the other ends, respectively, in the left-right direction. The connecting portion 56j of the extension 56 is rotatably (swingably) connected to the upper end of the first lift member 32 via a first connecting bolt 58, which serves as a first connecting pin. The first connecting bolt 58 is threadedly engaged with the upper end of the first lift member 32. The connecting portion 56c of the extension 56 is rotatably connected to the upper end of the second lift member 32 via a second connecting bolt 60, which serves as a second connecting pin. The second connecting bolt 60 is threadedly engaged with the upper end of the second lift member 32.

[0033] A support mechanism 62 is provided on the upper end of the first lifting member 32 to support the extension 56 from below. The support mechanism 62 includes a support base 64, which is provided on the upper end of the first lifting member 32 and extends inward in the left-right direction. The support mechanism 62 includes an adjustment screw 66, which is threadedly engaged with the front end of the support base 64 and contacts (supports) the extension 56 from below; and upper and lower lock nuts 68 and 70, which prevent the adjustment screw 66 from loosening. The support mechanism 62 adjusts the horizontality of the extension 56 by rotating the extension 56 about the first connecting bolt 58.

[0034] like Figure 3 、 Figure 5 and Figure 6 As shown, on the extension portion 56, a pair of Y-axis sliders 72 are provided so as to be movable in the left-right direction via a plurality of guide rails 74. Each Y-axis slider 72 extends in the front-back direction. A Y-axis motor 76 is provided on the back side of each Y-axis slider 72 to move each Y-axis slider 72 in the left-right direction relative to the extension portion 56. A rack component 78 is provided on the back side of the extension portion 56 to extend in the left-right direction. A pinion 80 is provided on the output shaft of each Y-axis motor 76, and each pinion 80 is engaged with the rack component 78. In addition, as an example, the drawings of the present application show a state in which the pair of Y-axis sliders 72 are most separated in the left-right direction.

[0035] An L-axis slider 82 is provided on the upper surface of each Y-axis slider 72 so as to be movable in the forward and backward directions via a pair of guide rails 84. An L-axis motor 86 is provided at the rear end of each Y-axis slider 72 to move each L-axis slider 82 in the forward and backward directions relative to each Y-axis slider 72. A ball screw 88 is rotatably provided on the upper surface of each Y-axis slider 72, extending in the forward and backward directions. Each ball screw 88 is interlockedly connected to the output shaft of each L-axis motor 86 via a coupling 90. A nut component 92 is provided at the rear end of each L-axis slider 82, and each nut component 92 is threadedly engaged with each ball screw 88.

[0036] like Figure 1 、 Figure 5 and Figure 6 As shown, an abutment base 94 is provided on the upper surface of each L-axis slider 82, and a mounting shaft 96 is provided at the front end of each abutment base 94. Each mounting shaft 96 is provided with an abutment member 98 having a known structure as described in Patent Document 2. In other words, a pair of abutment members 98 are provided on the extension portion 56 via a pair of Y-axis sliders 72 and a pair of L-axis sliders 82. Each abutment member 98 has an abutment surface 98f at its front end that can abut against the end surface Wf of the workpiece W. Each abutment member 98 is configured to be movable in the left-right direction and the front-back direction relative to the main frame 16. Each abutment member 98 is driven by the Y-axis motor 76 to move in the left-right direction relative to the main frame 16, integrally with the Y-axis slider 72. Each abutment member 98 is driven by the L-axis motor 86 to move in the front-back direction relative to the main frame 16, integrally with the L-axis slider 82. Each contact member 98 is detachably attached to each mounting shaft 96 and is configured to be able to spring up around the axis of each mounting shaft 96 .

[0037] Next, the operation and effects of the plate bender 10 according to this embodiment will be described.

[0038] (General function of the plate bender 10)

[0039] By driving the lifting motor 38 to raise and lower the pair of lifting members 32, the extending portion 56 and the pair of lifting members 32 are raised and lowered integrally, positioning the abutting surface 98 f of each abutting member 98 at a height corresponding to the lower mold 14. Furthermore, by driving the Y-axis motors 76, the abutting members 98 are moved in a horizontal direction integrally with the Y-axis slides 72, adjusting the horizontal spacing between the pair of abutting members 98 according to the bending length of the workpiece W. Furthermore, by driving the L-axis motors 86, the abutting members 98 are moved in a forward and backward direction integrally with the L-axis slides 82, positioning the abutting surface 98 f of each abutting member 98 at a predetermined position in the forward and backward direction.

[0040] The workpiece W is then moved rearward, causing its end surface Wf to abut against the abutment surfaces 98f of the pair of abutment members 98, thereby positioning the workpiece W in the front-to-back direction relative to the lower die 14. The upper table 24 is then lowered, and the upper die 12 and lower die 14 cooperate to bend the workpiece W. At this time, the abutment members 98 spring up about the axis of the mounting shafts 96, preventing damage to the abutment members 98 and other components caused by the springing of the workpiece W. After the workpiece W is bent, the upper table 24 is raised to return to its original position.

[0041] (Unique function of plate bender 10)

[0042] In the press brake 10, as described above, the connecting portion 56j of the extension portion 56 is rotatably connected to the upper end of the first lift member 32 via the first connecting bolt 58. The connecting portion 56c of the extension portion 56 is rotatably connected to the upper end of the second lift member 32 via the second connecting bolt 60. The second connecting bolt 60 is threadedly engaged with the upper end of the second lift member 32. A support mechanism 62 is provided at the upper end of the first lift member 32 to support the extension portion 56 from below. Multiple tension springs 52 are provided in parallel between the protrusion 30p of the second support block 30 and the extension 32e of the second lift member 32 to reduce the weight acting on the second lift member 32. Therefore, by simply providing the reverse stroke limiter 28 with a single lifting ball screw mechanism comprising the ball screw 36 and the nut member 48, the pair of lift members 32 can be raised and lowered by driving a single lifting motor 38.

[0043] Before bending the workpiece W, the power supply to the plate bender 10 is turned off, and the ball screw 36 is fixed to prevent rotation using the electromagnetic brake 50. Then, while the gravity acting on the second lifting member 32 is reduced by the plurality of tension springs 52, the adjustment screw 66 is rotated to rotate the extension portion 56 about the first connecting bolt 58, thereby horizontalizing the extension portion 56. This facilitates adjustment of the horizontality of the extension portion 56.

[0044] (Effect of plate bending machine 10)

[0045] According to this embodiment, as described above, by providing only one ball screw mechanism for raising and lowering the reverse stroke stopper 28, the pair of raising and lowering members 32 can be raised and lowered by driving a single raising and lowering motor 38, and the horizontality of the extension portion 56 can be easily adjusted. Therefore, according to this embodiment, the cost of the plate bending machine 10 can be reduced, and the adjustment operation of the reverse stroke stopper 28 can be simplified.

[0046] The present invention is not limited to the above-described embodiment and can be implemented in various other forms, for example, by appropriately modifying each support block 30 so that it can move forward and backward relative to the main frame 16. Furthermore, the scope of the technical solutions included in the present invention is not limited to the above-described embodiment.

[0047] The entire contents of Japanese Tokugawa Pharmacopoeia No. 2020-102874 (filing date: June 15, 2020) are incorporated herein by reference.

Claims

1. A plate bending machine, characterized in that: have: a pair of support blocks disposed on the back side of the lower workbench of the main frame and separated in the left-right direction; a lifting member, which is escalably provided on each of the pair of support blocks and extends in the up-down direction; a ball screw rotatably provided on the first lifting member of the pair of lifting members or the first support block of the pair of support blocks, extending in the vertical direction and rotated by the drive of the motor; a nut component, which is provided on the first supporting block or the first lifting component and is threadedly coupled to the ball screw; an extension portion, one end side of which in the left-right direction is connected to the upper end portion of the first lifting member, the other end side of which in the left-right direction is connected to the upper end portion of the second lifting member of the pair of lifting members, and extends in the left-right direction; an abutment member provided on the extension portion, having an abutment surface capable of abutting the end surface of the plate-shaped workpiece against the front end side, and configured to be movable in the front-rear direction relative to the main frame; a supporting mechanism, which is provided on the first lifting component and supports the extending portion from below; as well as a brake which fixes the ball screw against rotation, One end of the extending portion in the left-right direction is rotatably connected to the upper end of the first lifting member via a first connecting pin, and the other end of the extending portion in the left-right direction is rotatably connected to the upper end of the second lifting member via a second connecting pin. The support mechanism comprises: a supporting base, which is provided on the first lifting component; as well as An adjusting screw is threadably coupled to the support base and contacts the extending portion from below.

2. The plate bending machine according to claim 1, characterized in that A balancer is provided to reduce the gravity acting on the second lifting member.

3. The plate bending machine according to claim 2, characterized in that The balancer is a biasing member that is provided between the second support block of the pair of support blocks and the second lifting member and biases the second lifting member upward.

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