Insertion die device, press brake, and press brake bending method

Abstract

To improve the processing quality of a workpiece by performing bending processing using a die integrally molded with an ear part.SOLUTION: An insertion die device 6 comprises: an insertion die 17 which can be freely attached to / detached from a spacer die 16 attached to an upper holder 32 so as to be located between a plurality of upper dies 13 and performs bending processing to a workpiece W together with the plurality of upper dies 13 in a state of being attached to the spacer die 16; and a die movement mechanism 60 which moves the insertion die 17 between the attachment position where the insertion die 17 is attached to the spacer die 16 and the retreat position where the insertion die 17 is separated from the spacer die 16. The plurality of upper dies 13 include ear dies 15 integrally molded with ear parts 15d protruding to the lateral side on left and right ends.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inner die device, a press brake, and a bending method using a press brake. [Background technology]

[0002] Patent Document 1 discloses a punch die for box bending a workpiece, which has a movable ear on the side of the die body. One end of a link member is swingably supported on the side of the die body via a pin. The movable ear is attached to the other end of the link member via a pin. With this configuration, the movable ear hangs below the die body via the link member. When the punch die descends and abuts against the workpiece on the die, the movable ear moves and can reach its correct position relative to the die body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-76612 Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the technique disclosed in Patent Document 1, the movable ears are configured to be movable, which may cause unwanted movement of the movable ears during bending, which may affect the processing quality of the workpiece compared to when a die with integrally formed ears is used. [Means for solving the problem]

[0005] In one aspect of the present invention, a press brake is provided with a plurality of dies in close contact with each other, attached to a die holder provided on a table extending in the left-right direction, and the table is lowered relative to the workpiece to perform bending. The apparatus comprises an insert die configured to be detachable from a spacer die attached to a die holder so as to be positioned between a plurality of dies, and which performs bending processing on a workpiece together with the plurality of dies when attached to the spacer die, and a die moving mechanism which moves the insert die between an attachment position where the insert die is attached to the spacer die and a retracted position where the insert die is spaced apart from the spacer die, and the plurality of dies include ear dies at both left and right ends which have ears that protrude laterally and are integrally formed therewith.

[0006] According to one aspect of the present invention, an insert die device allows insert dies to be attached to or detached from a spacer die attached to a die holder. The overall width of the die attached to the die holder can be controlled by moving the dies arranged on the left and right of the spacer die depending on whether an insert die is attached or not. This allows for the required bending length to be achieved during bending while suppressing interference with the flange of the workpiece when using an ear die with an integrally formed ear. [Effects of the Invention]

[0007] According to one aspect of the present invention, bending can be performed using a die in which ear portions are integrally formed, thereby improving the processing quality of the workpiece. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view schematically showing the configuration of the insert mold device according to this embodiment. [Figure 2] FIG. 2 is a front view schematically showing the configuration of the press brake according to this embodiment. [Figure 3] FIG. 3 is a diagram illustrating the molds arranged along the upper holder. [Figure 4] FIG. 4 is an explanatory diagram showing an enlarged view of a main part of the insert die device. [Figure 5] FIG. 5 is an explanatory diagram showing the relationship between the insert mold and the spacer mold of the insert mold device. [Figure 6]FIG. 6 is a diagram illustrating the molds arranged along the upper holder. [Figure 7] FIG. 7 is a diagram illustrating the steps of a press brake bending method. [Figure 8] FIG. 8 is a diagram illustrating the steps of a press brake bending method. [Figure 9] FIG. 9 is a diagram illustrating the steps of a press brake bending method. [Figure 10] FIG. 10 is a diagram illustrating the steps of a press brake bending method. [Figure 11] FIG. 11 is a diagram illustrating the steps of a press brake bending method. [Figure 12] FIG. 12 is a diagram illustrating the steps of a press brake bending method. [Figure 13] FIG. 13 is a diagram illustrating the steps of a press brake bending method. [Figure 14] FIG. 14 is a diagram illustrating the steps of a press brake bending method. [Figure 15] FIG. 15 is a diagram illustrating the steps of a bending method using a press brake. [Figure 16] FIG. 16 is a diagram illustrating the steps of a press brake bending method. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes the inner die device, press brake, and press brake bending method according to this embodiment with reference to the drawings. In this specification, the definitions of directions are "left-right direction," "front-rear direction," and "up-down direction." The left-right direction and front-rear direction correspond to two directions that are perpendicular to the horizontal direction, and the up-down direction corresponds to the vertical direction. These directions are used merely for convenience in describing the configuration of the inner die device and press brake. Furthermore, "width" refers to the length in the left-right direction.

[0010] First, an outline of the insert die device according to this embodiment will be described with reference to Figures 1 to 3. Figure 1 is a side view that schematically shows the configuration of the insert die device according to this embodiment. Figure 2 is a front view that schematically shows the configuration of the press brake according to this embodiment. Figure 3 is a view that explains the dies that are arranged along the upper holder.

[0011] The intermediate die device 6 is mounted on a press brake 1 in which a plurality of upper dies 13 closely fitted to one another are attached to an upper holder 32 provided on an upper table 26 extending in the left-right direction, and the upper table 26 is lowered relative to the workpiece W to perform bending. The intermediate die device 6 is configured to be detachable from a spacer die 16 attached to the upper holder 32 so as to be positioned between the plurality of upper dies 13, and is equipped with an intermediate die 17 that performs the bending process on the workpiece W together with the plurality of upper dies 13 when attached to the spacer die 16, and a die moving mechanism 60 that moves the intermediate die 17 between an attachment position where the intermediate die 17 is attached to the spacer die 16 and a retracted position where the intermediate die 17 is separated from the spacer die 16. The plurality of upper dies 13 include ear dies 15 at both left and right ends, each having an integrally formed ear 15d that protrudes laterally.

[0012] The press brake 1 on which the inserting die device 6 is mounted will be described in detail with reference to FIGS.

[0013] As shown in Figure 2, the press brake 1 is a bending machine that performs bending processing on a plate-shaped workpiece W, such as sheet metal. A press brake main body 10 performs bending processing on the workpiece W through cooperation of a lower tool 11 such as a die and an upper tool 13 such as a punch. This embodiment is suitable for a press brake 1 that produces a box-shaped product having flange portions fw that extend inward on both the left and right sides by box bending the workpiece W.

[0014] The press brake 1 has a press brake body 10, left and right lower die exchange units 40L, 40R, left and right upper die exchange units 50L, 50R, an inner die device 6, and a control device 100.

[0015] The press brake body 10 includes a main body frame 18. The main body frame 18 has left and right side plates 20 that face each other and are spaced apart in the left-right direction. A lower table 24 extending in the left-right direction is provided below the main body frame 18, and an upper table 26 extending in the left-right direction is provided above the main body frame 18. The upper table 26 is configured to be movable in the vertical direction. An actuator, such as a hydraulic cylinder 28, that raises and lowers the upper table 26 in the vertical direction is provided above each side plate 20. Note that instead of raising and lowering the upper table 26 in the vertical direction, the lower table 24 may be raised and lowered in the vertical direction. A servo motor may be used as the actuator for vertical movement instead of the hydraulic cylinder 28.

[0016] A lower holder 30, on which the lower mold 11 is attached, is provided above the lower table 24. The lower holder 30 extends continuously in the left-right direction and is provided linearly across the entire area of ​​the lower table 24. A holder groove (not shown) for attaching the lower mold 11 is formed in the lower holder 30 along the left-right direction. The lower holder 30 has a hydraulic clamp unit (not shown) that performs a clamping operation to fix the lower mold 11 to the lower table 24.

[0017] An upper holder 32, to which the upper mold 13 is attached, is provided below the upper table 26. The upper holder 32 extends continuously in the left-right direction and is provided linearly across the entire area of ​​the upper table 26. A holder groove (not shown) for attaching the upper mold 13 is formed in the upper holder 32 along the left-right direction. The upper holder 32 has a hydraulic clamp unit (not shown) that performs a clamping operation to fix the upper mold 13 to the upper table 26.

[0018] Referring to Figure 3, the dies arranged along the upper holder 32 will be described. A plurality of upper dies 13 assembled for box bending are attached to the upper holder 32. The plurality of upper dies 13 include a plurality of split dies 14 and a set of selvedge dies 15 located on both the left and right ends. A spacer die 16, which is part of the insert die device 6, is also attached to the upper holder 32.

[0019] The split mold 14 is a mold for bending the workpiece W. The split mold 14 includes a workpiece processing section 14z that processes the workpiece W and a shank section 14a that is detachable from the holder groove of the upper holder 32. The shank section 14a of the split mold 14 is provided with an engagement piece 14b that catches on the holder groove to prevent the split mold 14 from falling out of the holder groove even when the clamping action by the clamp section is released. In addition, an insertion hole 14c is formed in the shank section 14a, penetrating it in the front-rear direction. The upper mold holding members 54L, 54R of the left and right upper mold replacement units 50L, 50R can be inserted into the insertion hole 14c. The mold width of the split mold 14 is set to be approximately the same from top to bottom.

[0020] The ear dies 15 are dies used to bend the workpiece W. The ear dies 15 share the same configuration as the split dies 14 and include a workpiece processing section 15z, a shank section 15a, an engagement piece 15b, and an insertion hole 15c. An ear 15d is provided at the bottom of the ear dies 15, protruding laterally along the die width direction (left-right direction). This ear 15d makes the die width at the center of the die smaller than the die width at the workpiece processing section 15z. By utilizing the recessed shape of the center of the side of the die, interference between the flange section fw of the workpiece W and the ear dies 15 during bending can be avoided. The ear dies 15 located at the left end include an ear 15d protruding to the left, and the ear dies 15 located at the right end include an ear 15d protruding to the right.

[0021] The spacer die 16 is a mounting member to which an inner die 17 (described later) is removably mounted, and does not have a substantial function (workpiece processing section) for processing the workpiece W. The spacer die 16 is mounted on the upper holder 32 so as to be positioned between the multiple upper dies 13, for example, in the center.

[0022] The spacer mold 16 has a shank portion 16a, an engagement piece 16b, and an insertion hole 16c, and is common to the split mold 14. The spacer mold 16 is provided with a positioning hole 16d for positioning the insert mold 17 and connecting to the insert mold 17. The mold width of the spacer mold 16 is smaller than the mold width of the split mold 14, and the mold height, which is the length of the spacer mold 16 in the up-down direction, is set smaller than the mold height of the split mold 14.

[0023] The total width Lt1 of the multiple upper dies 13 arranged with the spacer dies 16 between them is set smaller than the distance Lw1 from the tip of the right flange portion fw to the tip of the left flange portion fw of the work W. This makes it possible to suppress interference between the flange portion fw of the work W and the ear dies 15 on both the left and right ends when the upper table 26 is raised and lowered.

[0024] As shown in Fig. 2, a lower die 11 is attached to the lower holder 30. The lower die 11 is composed of, for example, a plurality of split dies 12. Although there is a difference in function between the lower die 11 and the upper die 13, the configuration of the split die 12 corresponds to the configuration of the split die 14, and therefore a detailed description thereof will be omitted. As shown in Fig. 3, the overall width of the lower die 11 including the plurality of split dies 12 corresponds to the bending length of the workpiece W.

[0025] 2, a die rack 34 is provided adjacent to one of the left and right sides of the press brake body 10 (on the right side in this embodiment). The die rack 34 stores a plurality of lower dies 11, a plurality of upper dies 13, and a spacer die 16.

[0026] The left and right upper mold exchange units 50L, 50R exchange the upper mold 13 between the upper holder 32 and the mold rack 34, and move and position the upper mold 13 attached to the upper holder 32. The left and right upper mold exchange units 50L, 50R are provided on the rear side of the upper table 26. An upper guide 38 extending in the left-right direction is provided on the rear side of the upper holder 32. Each upper mold exchange unit 50L, 50R is equipped with an actuator for left-right movement, such as a servo motor, and can move in the left-right direction via the upper guide 38.

[0027] The left and right upper mold exchange units 50L, 50R have upper mold holding members 54L, 54R that can be inserted into the insertion holes (insertion holes 14c, 15c, 16c shown in FIG. 3) of the upper mold 13 and the spacer mold 16. Each upper mold holding member 54L, 54R can move in the front-to-rear direction by driving an actuator for front-to-rear movement, such as an air cylinder, or can move in the up-to-down direction by driving an actuator for up-to-down movement, such as an air cylinder.

[0028] Each upper mold exchange unit 50L, 50R can hold the upper mold 13 and the spacer mold 16 by advancing the upper mold holding members 54L, 54R and inserting them into the insertion holes of the upper mold 13 and the spacer mold 16. With the upper mold holding members 54L, 54R holding the upper mold 13 and the spacer mold 16, the upper mold exchange units 50L, 50R move in the left-right direction. Through this movement, the upper mold 13 and the spacer mold 16 can be attached to the upper holder 32 from the left-right ends, or the upper mold 13 and the spacer mold 16 attached to the upper holder 32 can be moved. Then, when the upper mold exchange units 50L, 50R stop at a predetermined position, the upper mold 13 and the spacer mold 16 can be positioned at a target position in the upper holder 32.

[0029] The left and right upper mold exchange units 50L, 50R can independently move and position the upper mold 13 and the spacer mold 16. In this case, the left and right upper mold exchange units 50L, 50R may attach the upper mold 13 and the spacer mold 16 to the upper holder 32 from the left and right ends of the upper holder 32 and position them to the target positions from there, or alternatively, the upper mold 13 and the spacer mold 16 may be directly attached to the target positions of the upper holder 32 from the lower side of the upper holder 32 in the up-down direction. However, the left and right upper mold exchange units 50L, 50R may hold the upper molds 13 at both left and right ends of the multiple upper molds 13 and spacer molds 16 lined up in the left-right direction, respectively, and sandwich the upper molds 13 and spacer molds 16 between the left and right upper molds 13, thereby simultaneously moving and positioning the multiple upper molds 13 and spacer molds 16.

[0030] The left and right lower mold exchange units 40L, 40R exchange the lower mold 11 between the lower holder 30 and the mold rack 34, and move and position the lower mold 11 attached to the lower holder 30. The configuration of the left and right lower mold exchange units 40L, 40R corresponds to the configuration of the left and right upper mold exchange units 50L, 50R, including the fact that they are equipped with lower mold holding members 44L, 44R, etc.

[0031] As shown in FIG. 1 , the intermediate die device 6 is a device for attaching an intermediate die 17 to a spacer die 16 located between multiple upper dies 13 attached to an upper holder 32, and for removing the intermediate die 17 from the spacer die 16. By inserting the intermediate die 17 between multiple upper dies 13 through attachment and detachment to and from the spacer die 16, the overall width of the die required for the bending length of the workpiece W can be ensured. Furthermore, by removing the intermediate die 17 from between multiple upper dies 13 through attachment and detachment to and from the spacer die 16, the overall width of the die can be shortened. This makes it possible to suppress interference between the flange portion fw of the workpiece W and the edge die 15 when the upper table 26 is raised and lowered. A detailed description of the intermediate die device 6 will be given later.

[0032] The control device 100 is a device that controls the operation of the press brake 1. The control device 100 is, for example, a computer such as an NC (Numerical Control) device. The computer is mainly composed of a hardware processor such as a CPU (Central Processing Unit), a memory, and various interfaces. The memory and various interfaces are connected to the hardware processor via a bus.

[0033] A predetermined computer program is installed in the computer, and the computer executes the functions of the control device 100 by the hardware processor executing the computer program.

[0034] The control device 100 controls the operation of the press brake main body 10 based on the processing program. The control device 100 also controls the operations of the left and right lower die exchange units 40L, 40R, the left and right upper die exchange units 50L, 50R, and the inner die device 6. This control allows the upper table 26 to be raised and lowered, the upper die 13 to be attached and moved to the upper holder 32, and the inner die 17 to be attached and detached.

[0035] The insert mold device 6 will be described below with reference to Figures 1, 4, and 5. Figure 4 is an explanatory diagram showing an enlarged view of the main parts of the insert mold device. Figure 5 is an explanatory diagram showing the relationship between the insert mold and the spacer mold of the insert mold device.

[0036] The inserting mold device 6 is composed of the above-mentioned spacer mold 16, the inserting mold 17, and a mold moving mechanism 60. The inserting mold device 6 is provided on the rear side of the upper table 26.

[0037] The inner die 17 is configured to be detachable from the spacer die 16. The inner die 17, when attached to the spacer die 16 attached to the upper holder 32, performs bending on the workpiece W together with the plurality of upper dies 13. The inner die 17 is connected to a die moving mechanism 60.

[0038] 5, the insert die 17 has a workpiece processing section 17z that performs bending processing on the workpiece W. The insert die 17 has a connecting pin 17a that protrudes forward. The connecting pin 17a is inserted into a positioning hole 16d of the spacer die 16 to align the spacer die 16 and the insert die 17 and connect them together.

[0039] Left and right fixed blocks 17b are provided on the sides of the connecting pin 17a, spaced apart in the left-right direction according to the width of the spacer mold 16. When the insert mold 17 is connected to the spacer mold 16, the left and right fixed blocks 17b are adjacent to the left and right sides of the spacer mold 16. The spacer mold 16 comes into close contact with the left and right fixed blocks 17b, thereby creating a unity between the insert mold 17 and the spacer mold 16. This makes it possible to suppress rattling of the insert mold 17.

[0040] 1, the mold moving mechanism 60 holds the insert mold 17 and moves the insert mold 17. The mold moving mechanism 60 includes a movable arm 62, a fixed plate 64, a movable block 66, a fixed bracket 68, a swing drive unit 70, and a front-rear drive unit 72.

[0041] The upper end of the movable arm 62 is pivotally supported by a rotary shaft 74 provided on the rear surface of the upper table 26. Driven by a swing drive unit 70 constituted by an air cylinder or the like, the lower end of the movable arm 62 swings around the rotary shaft 74. The movable arm 62 is movable between a first position in which it hangs down along the upper table 26 and a second position in which it is inclined at a predetermined angle relative to the upper table 26.

[0042] A fixed plate 64 is attached to the lower end of the movable arm 62. A movable block 66 configured to be movable in the front-rear direction is provided on the underside of the fixed plate 64. The movable block 66 moves in the front-rear direction by driving a front-rear drive unit 72 configured by an air cylinder or the like. A fixed bracket 68 is attached to the front end of the movable block 66, and the insert mold 17 is fixed to the fixed bracket 68.

[0043] 4, the fixed bracket 68 is attached to the movable block 66 by inserting a shaft 76 provided on the movable block 66 into a through-hole in the fixed bracket 68. At this time, a required gap G is provided between the fixed bracket 68 and a flange-shaped stopper portion 76a at the upper end of the shaft 76. This gap G allows the fixed bracket 68 to move slightly in the vertical direction.

[0044] As shown in FIG. 1, the swing drive unit 70 drives the movable arm 62 to swing, allowing the inner mold 17 to move within a range from a retracted position P1 to an intermediate position P2. The retracted position P1 is the position within the swing range of the movable arm 62 where the inner mold 17 is farthest from the spacer mold 16. This retracted position P1 is set so that the inner mold 17 and the mold moving mechanism 60 do not interfere with the left and right upper mold exchange units 50L, 50R even when the left and right upper mold exchange units 50L, 50R move left and right. On the other hand, the intermediate position P2 is the position within the swing range of the movable arm 62 where the inner mold 17 is closest to the spacer mold 16. The inner mold 17 at the intermediate position P2 faces the spacer mold 16 at a certain distance behind it.

[0045] When the insert die 17 is in the intermediate position P2, the movable block 66 is moved forward and backward by the drive of the front-rear drive unit 72, allowing the insert die 17 to move within a range from the intermediate position P2 to the mounting position P3. The mounting position P3 is the position where the insert die 17 is mounted to the spacer die 16. When the insert die 17 is in the mounting position P3, the connecting pin 17a of the insert die 17 enters the positioning hole 16d of the spacer die 16, and the spacer die 16 enters between the left and right fixed blocks 17b of the insert die 17. The connecting pin 17a entering the positioning hole 16d restricts the movement of the insert die 17 in the up-down and left-right directions. Similarly, the fixed blocks 17b are in close contact with the left and right sides of the spacer die 16, restricting the movement of the insert die 17 in the left-right direction and restricting the rotation of the insert die 17 around the connecting pin 17a. This results in a tight connection between the insert mold 17 and the spacer mold 16. Since the mold moving mechanism 60 is connected to the insert mold 17, while the insert mold 17 is attached to the spacer mold 16, the mold moving mechanism 60 operates to hold the insert mold 17 at the attachment position P3.

[0046] FIG. 6 is a diagram illustrating the molds arranged along the upper holder. The mold moving mechanism 60 moves the insert mold 17 to the mounting position P3, allowing the insert mold 17 to be mounted on the spacer mold 16. When mounted on the spacer mold 16, the insert mold 17 surrounds the left and right sides and the bottom of the spacer mold 16. Therefore, the split mold 14 and the ear mold 15 located to the left of the spacer mold 16 are positioned at a position offset to the left compared to the mold arrangement shown in FIG. 3. Similarly, the split mold 14 and the ear mold 15 located to the right of the spacer mold 16 are positioned at a position offset to the right compared to the mold arrangement shown in FIG. 3.

[0047] The overall width Lt2 of the multiple upper dies 13 arranged with the intermediate die 17 between them is longer than the overall width Lt1 shown in Fig. 3 by the length obtained by subtracting the die width Lt4 of the spacer die 16 from the die width Lt3 of the intermediate die 17. This makes it possible to obtain the overall width Lt2 corresponding to the bending length Lw2 required for bending the workpiece W.

[0048] 3, it is necessary to suppress interference between the flange portion fw of the workpiece W and the stage of the upper die 13 when the upper table 26 is raised or lowered. Therefore, the die width Lt3 of the inner die 17, the die width Lt4 of the spacer die 16, and the widths Lt5 and Lt6 of the ear portions 15d of the left and right ear dies 15 satisfy the relationship shown in the following mathematical formula. (Equation 1) Lt3-Lt4≧Lt5+Lt6

[0049] In this embodiment, five split dies 14 are arranged between the inner die 17 (spacer die 16) and the left and right ear dies 15, respectively, but the number of split dies 14 is not limited to this. The number of split dies 14 can be selected taking into consideration the die width of the split dies 14, the bending length Lw2 of the workpiece W, etc. Furthermore, the inner die 17 (spacer die 16) is arranged in the center of the multiple upper dies 13, but it may also be arranged in a position shifted from the center. In other words, the number of upper dies 13 arranged on both sides of the inner die 17 (spacer die 16) may be different. Furthermore, a configuration in which no split dies 14 are arranged between the inner die 17 (spacer die 16) and the left and right ear dies 15 may be used.

[0050] The bending method of the press brake 1 of this embodiment will be described below with reference to Figures 1, 3, and 7 to 16. Figures 7 to 16 are diagrams illustrating the steps of the bending method of the press brake. Each step included in this bending method is performed by the control device 100 controlling each part of the press brake 1. However, any step in the bending method may also be performed by an operator.

[0051] In the following description, as shown in Figures 7 to 16, a bending process will be exemplified in which a workpiece W having flange portions fw on both the left and right sides is bent. In the initial state, it is assumed that no dies are attached to the lower holder 30 and the upper holder 32. It is also assumed that the inner die 17 of the inner die device 6 is located at the retracted position P1.

[0052] 7, the control device 100 controls the left and right upper mold exchange units 50L, 50R to mount the required upper molds 13 and spacer molds 16 on the upper holder 32. Mounted on the upper holder 32 from left to right are an ear mold 15 having an ear 15d on the left side, five split molds 14, a spacer mold 16, five split molds 14, and an ear mold 15 having an ear 15d on the right side.

[0053] Next, the control device 100 controls the left and right upper mold exchange units 50L and 50R to position the spacer mold 16 so that the positioning holes 16d of the spacer mold 16 are aligned with the positions of the connecting pins 17a of the insert mold 17. Additionally, the control device 100 controls the left and right upper mold exchange units 50L and 50R to perform a moving operation. The moving operation is an operation to close the gaps between the upper molds 13 arranged in the upper holder 32 and bring them into close contact with each other. Specifically, the control device 100 moves the five split molds 14 and the edge molds 15 arranged to the left of the spacer mold 16 and the five split molds 14 and the edge molds 15 arranged to the right of the spacer mold 16 toward the spacer mold 16 so that they come into close contact with the spacer mold 16 (moving process (first process)). As shown in FIG. 3 , the overall width Lt1 of the multiple upper molds 13 arranged across the spacer mold 16 is smaller than the spacing Lw1.

[0054] Similarly, the control device 100 controls the left and right lower die exchange units 40L, 40R to attach the lower die 11 to the lower holder 30. The overall width of the attached lower die 11 corresponds to the bending length of the workpiece W.

[0055] Next, the control device 100 controls the clamping portions of the lower holder 30 and the upper holder 32 to perform the clamping operation of the lower die 11, the upper die 13, and the spacer die 16. After the clamping operation, the workpiece W having flange portions fw on the left and right sides is placed on the lower die 11.

[0056] 8, the control device 100 drives the hydraulic cylinder 28 to lower the upper table 26 to a first lowered position Pd1. The first lowered position Pd1 is located a predetermined distance above the position where the workpiece W is pressed (bottom dead center).

[0057] The control device 100 controls the clamping portion of the upper holder 32 to perform an unclamping operation to release the upper mold 13 from its fixed state.

[0058] As shown in FIG. 9, the control device 100 controls the left and right upper die exchange units 50L, 50R to move the five split dies 14 and ear dies 15 arranged to the right of the spacer die 16 in a direction away from the spacer die 16 (to the right) (movement process (second process)). As a result, the ear portion 15d of the right ear die 15 is inserted into the right flange portion fw of the workpiece W. Similarly, the control device 100 controls the left and right upper die exchange units 50L, 50R to move the five split dies 14 and ear dies 15 arranged to the left of the spacer die 16 in a direction away from the spacer die 16 (to the left) (movement process (second process)). As a result, the ear portion 15d of the left ear die 15 is inserted into the left flange portion fw of the workpiece W.

[0059] The movement amount of each of the five split dies 14 and the ear dies 15 arranged to the right of the spacer die 16 and the five split dies 14 and the ear dies 15 arranged to the left of the spacer die 16 is about half the die width of the insert die 17. This leaves spaces on the left and right sides of the spacer die 16 for inserting the insert die 17.

[0060] As shown in Fig. 10, the control device 100 controls the insert mold device 6 to insert the insert mold 17 into the space between the molds and attach the insert mold 17 to the spacer mold 16 (attaching process). Specifically, as shown in Fig. 1, the control device 100 drives the swing drive unit 70 to move the insert mold 17 from the retracted position P1 to the intermediate position P2. Then, the control device 100 drives the front-rear drive unit 72 to move the insert mold 17 from the intermediate position P2 to the attachment position P3.

[0061] When the inner mold 17 moves from the intermediate position P2 to the mounting position P3, the connecting pin 17a of the inner mold 17 is inserted into the positioning hole 16d of the spacer mold 16. This allows the spacer mold 16 and the inner mold 17 to be aligned and connected together.

[0062] In addition, the fixed blocks 17b on the left and right of the connecting pin 17a are in close contact with the left and right sides of the spacer mold 16. This creates a unity between the insert mold 17 and the spacer mold 16, making it possible to suppress rattling of the insert mold 17.

[0063] As shown in Fig. 11, the control device 100 controls the left and right upper mold exchange units 50L, 50R to perform a moving operation. Specifically, the control device 100 moves the five split molds 14 and the ear molds 15 arranged on the right side of the insert mold 17 toward the insert mold 17 (left side) so that they come into close contact with the insert mold 17 (moving process (third process)). Similarly, the control device 100 moves the five split molds 14 and the ear molds 15 arranged on the left side of the insert mold 17 toward the insert mold 17 (right side) so that they come into close contact with the insert mold 17 (moving process (third process)).

[0064] The control device 100 controls the clamping portion of the upper holder 32 to perform the clamping operation for the upper mold 13. When the clamping operation is performed, a force pushing the upper mold 13 obliquely upward acts from the clamping portion on the upper mold 13 attached to the upper holder 32. Therefore, the clamping operation causes the upper mold 13 to move slightly upward.

[0065] At this time, the spacer die 16 attached to the upper holder 32 also moves upward. As shown in FIG. 4, the fixed bracket 68 to which the inner die 17 is fixed can move slightly in the vertical direction along the shaft 76. Therefore, as shown in FIG. 12, the inner die 17 attached to the spacer die 16 is dragged by the spacer die 16 and moves upward. This upward movement brings the upper surface of the inner die 17, i.e., the surface that receives the pressure force during bending, into tight contact with the lower surface of the upper holder 32. This creates a unity between the inner die 17 and the upper holder 32, thereby suppressing rattling of the inner die 17.

[0066] 13, the control device 100 drives the hydraulic cylinder 28 to lower the upper table 26 from the first lowered position Pd1 to the second lowered position Pd2 corresponding to the bottom dead center. As a result, the workpiece W is pressed by the upper dies 13 and the middle dies 17, and the lower die 11. Then, the control device 100 drives the hydraulic cylinder 28 to raise the upper table 26 from the second lowered position Pd2 to the first lowered position Pd1 (bending process).

[0067] 14, when the upper table 26 is raised to the first lowered position Pd1, the workpiece W is returned to a horizontal position. Then, the workpiece W is moved horizontally backward by an operator or a robot arm. The amount of backward movement of the workpiece W only needs to be greater than the amount of movement of the inner insert die 17 when it moves from the mounting position P3 to the intermediate position P2.

[0068] Next, the control device 100 controls the clamping unit of the upper holder 32 to perform an unclamping operation of the upper mold 13. The control device 100 also drives the front-rear drive unit 72 to move the inner mold 17 from the mounting position P3 to the intermediate position P2. As a result, the inner mold 17 is removed from the spacer mold 16 (removal process).

[0069] As shown in FIG. 15, the control device 100 controls the left and right upper mold replacement units 50L, 50R to perform a moving operation. Specifically, the control device 100 moves the five split molds 14 and the ear molds 15 arranged on the right side of the spacer mold 16 toward the spacer mold 16 (left side) so as to come into close contact with the spacer mold 16 (moving step (fourth step)). Similarly, the control device 100 moves the five split molds 14 and the ear molds 15 arranged on the left side of the spacer mold 16 toward the spacer mold 16 (right side) so as to come into close contact with the spacer mold 16 (moving step (fourth step)). As a result, the upper molds 13 arranged in the upper holder 32 are moved together around the spacer mold 16 and arranged without any gaps between them. At this time, the overall width Lt1 of the multiple upper molds 13 arranged across the spacer mold 16 becomes smaller than the interval Lw1 (see FIG. 3).

[0070] Then, the control device 100 controls the clamping portion of the upper holder 32 to perform the clamping operation of the upper mold 13 and the spacer mold 16.

[0071] 16, the control device 100 drives the hydraulic cylinder 28 to raise the upper table 26 from the first lowered position Pd1 to a position corresponding to the top dead center. At this time, the ear dies 15 located at both the left and right ends are moved toward the spacer die 16. The upper table 26 can be raised without interference between the ear portions 15d and the flange portion fw of the workpiece W.

[0072] Finally, as shown in FIG. 1, the control device 100 drives the swing drive unit 70 to move the insert mold 17 from the intermediate position P2 to the retracted position P1.

[0073] Through this series of steps, the bending of the workpiece W is completed.

[0074] As described above, with the press brake 1 and inner die device 6 of this embodiment, the inner die 17 can be attached to or detached from the spacer die 16 attached to the upper holder 32. By moving the upper dies 13 arranged on the left and right of the spacer die 16 depending on whether the inner die 17 is attached or not, the overall widths Lt1 and Lt2 of the die attached to the upper holder 32 can be controlled. When using an ear die 15 with an integrally formed ear portion 15d, it is possible to obtain the required bending length during bending while suppressing interference with the flange portion fw of the workpiece W.

[0075] This allows the bending process to be performed using the ear mold 15 in which the ear portion 15d is integrally formed, thereby improving the processing quality of the workpiece W.

[0076] Furthermore, the inner mold 17 is not directly attached to the upper holder 32, but is attached to the spacer mold 16, and is thereby indirectly attached to the upper holder 32 via the spacer mold 16. Therefore, the inner mold 17 can be easily arranged between a plurality of upper molds 13 already attached to the upper holder 32.

[0077] In this embodiment, the mold moving mechanism 60 is coupled to the insert mold 17 and holds the insert mold 17 at the mounting position P3 while the insert mold 17 is mounted on the spacer mold 16.

[0078] According to this configuration, the mold moving mechanism 60 holds the insert mold 17 at the mounting position P3, so that the insert mold 17 can be maintained in a state where it is mounted on the spacer mold 16.

[0079] In this embodiment, the mold moving mechanism 60 moves the insert mold 17 to the mounting position P3 in a state in which the molds are switched from a first state in which multiple upper molds 13 are closely attached around the spacer mold 16 to a second state in which each of the upper molds 13 adjacent to the left and right of the spacer mold 16 is spaced apart from the spacer mold 16 in the left-right direction.

[0080] According to this configuration, the insert mold 17 can be attached to the spacer mold 16 without interfering with the upper molds 13 adjacent to the left and right of the spacer mold 16.

[0081] In this embodiment, the inner mold 17 is attached to the spacer mold 16 and is positioned below the upper holder 32. When the spacer mold 16 is pulled upward in accordance with the clamping operation of the upper holder 32, the inner mold 17 attached to the spacer mold 16 is also pulled upward, and the upper surface of the inner mold 17 comes into close contact with the lower surface of the upper holder 32.

[0082] With this configuration, the upper surface of the inner die 17, i.e., the surface that receives pressure during bending, is in close contact with the lower surface of the upper holder 32. Compared to a state in which the inner die 17 is simply attached to the spacer die 16, the inner die 17 and the upper holder 32 are more integrated. This makes it possible to suppress rattle of the inner die 17, thereby improving the quality of the bending process.

[0083] In this embodiment, the mold moving mechanism 60 includes a fixed bracket 68 to which the insert mold 17 is fixed. The fixed bracket 68 is configured to be movable in the mold moving mechanism 60 in the up and down direction.

[0084] According to this configuration, the inner mold 17 can move up and down via the fixed bracket 68. As a result, the upper surface of the inner mold 17 can be brought into close contact with the lower surface of the upper holder 32 as the upper holder 32 clamps.

[0085] In this embodiment, the mold moving mechanism 60 further includes (a) a movable arm 62 whose upper end is pivotally supported on the rear surface of the upper table 26 and whose lower end is configured to swing, and which is movable between a first position in which it hangs down along the upper table 26 and a second position inclined at a predetermined angle relative to the upper table 26, and (b) a movable block 66 disposed at the lower end of the movable arm 62 so as to be movable in the front-to-rear direction. A fixed bracket 68 is attached to the movable block 66 and is configured so as to be movable in the up-and-down direction.

[0086] According to this configuration, the inner die 17 can be appropriately moved between the mounting position P3 and the waiting position P1. Also, by retracting the movable arm 62 to the waiting position P1 while swinging, a large space can be created behind the upper holder 32. This makes it possible to suppress interference between the left and right upper die exchange units 50L, 50R and the inner die 17. Also, during bending processing that does not use the inner die 17, it is possible to suppress a situation in which the inner die 17 at the waiting position P1 interferes with the workpiece W.

[0087] In this embodiment, the insert mold 17 faces the rear of the spacer mold 16 when the movable arm 62 is in the first position, and reaches the mounting position P3 by the movable block 66 advancing forward.

[0088] With this configuration, the insert mold 17 moves between the mounting position P3 and the retracted position P1 due to the swinging of the movable arm 62 and the back-and-forth movement of the movable block 66. Through the back-and-forth movement, the coupling pin 17a of the insert mold 17 can be inserted into the positioning hole 16d of the spacer mold 16, so that when the insert mold 17 is mounted on the spacer mold 16, the two can be properly aligned and coupled. Furthermore, when the insert mold 17 is in the retracted position P1, a larger space can be created behind the upper holder 32.

[0089] In this embodiment, the upper holder 32 extends continuously and linearly in the left-right direction. The spacer mold 16 and the plurality of upper molds 13 are attached to the upper holder 32 from the left-right ends of the upper holder 32 or from the lower side of the upper holder 32 in the up-down direction.

[0090] The inner die 17 is not directly attached to the upper holder 32, but is attached to the spacer die 16, and thereby indirectly attached to the upper holder 32. Therefore, even when the upper table 26 is in the first lowered position Pd1, that is, when the spacer die 16 and the plurality of upper dies 13 are present between the left and right flange portions fw of the workpiece W, and the upper dies 13 cannot be removed from the left and right ends of the upper holder 32 or from the bottom in the vertical direction, the inner die 17 can be easily positioned.

[0091] In this embodiment, the bending method of the press brake 1 includes: (a) an attachment step of attaching to the upper holder 32 a plurality of upper dies 13, each having an ear die 15 integrally formed with laterally projecting ear portions 15d and arranged on both the left and right ends, and a spacer die 16 arranged between the plurality of upper dies 13; and (b) a movement step of moving the upper die 13 arranged to the left of the spacer die 16 and the upper die 13 arranged to the right of the spacer die 16, respectively, about the spacer die 16. The spacer die 16 is a mounting member on which an insert die 17 that performs bending on the workpiece W is removably attached.

[0092] According to this method, the overall widths Lt1 and Lt2 of the dies attached to the upper holder 32 can be controlled by moving the upper dies 13 arranged on the left and right sides of the spacer die 16 depending on whether or not the insert die 17 is attached. As a result, when using an ear die 15 having an integrally formed ear 15d, it is possible to obtain the required bending length during bending while suppressing interference with the flange portion fw of the workpiece W. Furthermore, since bending can be performed using an ear die 15 having an integrally formed ear 15d, the processing quality of the workpiece W can be improved.

[0093] In this embodiment, the moving process includes a first process of moving the upper mold 13 arranged to the left of the spacer mold 16 and the upper mold 13 arranged to the right of the spacer mold 16 toward the spacer mold 16 so that they are in close contact with the spacer mold 16, and a second process of moving the upper mold 13 arranged to the left of the spacer mold 16 and the upper mold 13 arranged to the right of the spacer mold 16 away from the spacer mold 16, thereby forming spaces on the left and right sides of the spacer mold 16 into which the insert mold 17 can enter.

[0094] According to this method, when using an ear mold 15 in which the ear portion 15d is integrally formed, it is possible to obtain the required bending length during bending while suppressing interference with the flange portion fw of the workpiece W.

[0095] In the bending method of the press brake 1 of this embodiment, after the first step, the upper table 26 is lowered relative to the workpiece W, and the lowering is stopped when the upper table 26 reaches the first lowering position Pd1, after which the second step is performed.

[0096] According to this method, even when an ear mold 15 having an integrally formed ear portion 15d is used, it is possible to prevent the ear mold 15 from interfering with the flange portion fw of the workpiece W when the upper table 26 is lowered.

[0097] The bending method using the press brake 1 of this embodiment further includes an attachment step of attaching the insert die 17 to the spacer die 16 after the second step.

[0098] According to this method, the insert mold 17 can be attached to the spacer mold 16 without interfering with the upper molds 13 adjacent to the left and right of the spacer mold 16.

[0099] In this embodiment, the moving process further includes a third process of moving the upper mold 13, which is positioned to the left of the inner mold 17, and the upper mold 13, which is positioned to the right of the inner mold 17, toward the spacer mold 16 (inner mold 17) so that they are in close contact with the inner mold 17 when the inner mold 17 is attached to the spacer mold 16.

[0100] According to this method, the dies arranged in the upper holder 32 can be laid out without any gaps, thereby enabling the bending process to be carried out appropriately.

[0101] In this embodiment, the inner mold 17 is positioned below the upper holder 32 while attached to the spacer mold 16, and when the spacer mold 16 is pulled upward as the upper holder 32 clamps, the inner mold 17 attached to the spacer mold 16 is also pulled upward, and the upper surface of the inner mold 17 comes into close contact with the lower surface of the upper holder 32.

[0102] The bending method of the press brake 1 of this embodiment further includes a bending process in which the upper table 26 is lowered relative to the workpiece W from the first lowered position Pd1 to the second lowered position Pd2, and then the upper table 26 is raised relative to the workpiece W to the first lowered position Pd1, and a removal process in which the workpiece W is moved horizontally backward, and then the insert die 17 is moved backward to remove the insert die 17 from the spacer die 16.

[0103] This method can prevent interference between the workpiece W that has been bent in the bending process and the insert die 17 that moves backward. This allows the insert die 17 to be removed, and also ensures that the workpiece W is properly protected.

[0104] In this embodiment, the moving step includes a fourth step in which, after the removing step, the upper die 13 arranged on the left side of the spacer die 16 and the upper die 13 arranged on the right side of the spacer die 16 are moved toward the spacer die 16 so as to come into close contact with the spacer die 16. Then, after the fourth step, the upper table 26 is raised from the first lowered position Pd1 relative to the workpiece W.

[0105] According to this method, it is possible to shorten the overall width Lt1 of the mold attached to the upper holder 32 before the upper table 26 is raised. This makes it possible to avoid interference between the ear mold 15, which has the ear portion 15d integrally formed therewith, and the flange portion fw of the workpiece W.

[0106] In this embodiment, the press brake 1 includes left and right upper tool exchange units 50L and 50R as moving bodies, whereby the moving process can be automatically performed by the left and right upper tool exchange units 50L and 50R.

[0107] In this embodiment, the press brake 1 is provided with the insert die device 6 behind the upper table 26. This allows the insert die 17 to be automatically attached to the spacer die 16.

[0108] Although the embodiments of the present invention have been described above, the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure. [Explanation of symbols]

[0109] 1. Press brake 6 Inserting mold device 10 Press brake body 11 Lower mold 12 Split mold 13 Upper mold (mold) 14 Split mold 15 Ear mold 15d Ears 16 Spacer mold 17 Inserting mold 24 Lower Table 26 Upper table (table) 30 Lower holder 32 Upper holder (mold holder) 34 mold rack 40L, 40R lower die change unit 44L, 44R Lower die holding member 50L, 50R Upper die change unit (moving body) 54L, 54R Upper mold holding member (mold holding member) 60 Mold moving mechanism 62 Movable arm 64 Fixing plate 66 Movable Block 68 Fixing bracket 70 Swing drive unit 72 Front and rear drive unit 74 Rotational Axis 76 Shaft 76a Stopper part 100 control device fw flange part G Gap Lt1, Lt2 Overall width of the mold Lt3, Lt4 mold width Lt5, Lt6 Width of ear Lw1 interval Lw2 bending length P1 Waiting position P2 intermediate position P3 mounting position Pd1 1st lowering position Pd2 2nd lowering position double work

Claims

1. In a press brake in which a plurality of dies in close contact with each other are attached to a die holder provided on a table extending in the left-right direction, and the table is lowered relative to a workpiece to perform bending, the press brake is equipped with an inner die device, an inserting die configured to be detachable from a spacer die attached to the die holder so as to be positioned between the plurality of dies, and which performs the bending process on the workpiece together with the plurality of dies when attached to the spacer die; a mold moving mechanism that moves the insert mold between an attachment position where the insert mold is attached to the spacer mold and a retreat position where the insert mold is separated from the spacer mold, The plurality of molds include ear molds at both the left and right ends, each having an ear portion integrally formed therein and projecting laterally, the insert die is positioned below the die holder in a state where it is attached to the spacer die, When the spacer mold is pulled up in accordance with the clamping operation of the mold holder, the insert mold attached to the spacer mold is also pulled up, and the upper surface of the insert mold comes into close contact with the lower surface of the mold holder. Inserting mold device.

2. The mold moving mechanism includes: a spacer die coupled to the insert die and holding the insert die in the installed position while the insert die is installed in the spacer die; The insert mold device according to claim 1.

3. The mold moving mechanism includes: The inserting die is moved to the mounting position in a state where the die is switched from a first state in which the die is in close contact with the spacer die at the center to a second state in which the die adjacent to the left and right of the spacer die are spaced apart from the spacer die in the left-right direction.

3. The insert mold device according to claim 1 or 2.

4. The mold moving mechanism includes: A fixing bracket is provided to which the inserting die is fixed, The fixing bracket is The mold moving mechanism is configured to be movable in the vertical direction. The insert mold device according to any one of claims 1 to 3.

5. The mold moving mechanism includes: a movable arm whose upper end is pivotally supported on the rear surface of the table and whose lower end is configured to swing, and which is movable between a first position in which it hangs down along the table and a second position in which it is inclined at a predetermined angle with respect to the table; a movable block disposed at a lower end of the movable arm and movable along a front-rear direction, The fixing bracket is The movable block is attached to the movable block and is configured to be movable in the vertical direction relative to the movable block. The insert mold device according to claim 4.

6. The insert mold is When the movable arm is in the first position, it faces the rear of the spacer mold, and the movable block advances forward to reach the mounting position. The insert mold device according to claim 5.

7. The mold holder includes: It extends continuously and linearly along the left-right direction, The spacer mold and the plurality of molds are The mold holder is attached to the mold holder from the left and right ends of the mold holder, or from the lower side of the mold holder in the up and down direction. The insert mold device according to any one of claims 1 to 6.

8. a press brake body in which a plurality of dies in close contact with each other are attached to a die holder provided on a table extending in the left-right direction, and the table is lowered relative to the workpiece to perform bending; The insert mold device according to any one of claims 1 to 7, A press brake equipped with

9. In a press brake bending method, a table on which die holders are provided in the left-right direction is lowered relative to a workpiece to perform bending, a mounting step of mounting a plurality of molds, each having an ear mold integrally formed with a laterally protruding ear portion, at both left and right ends thereof, and a spacer mold disposed between the plurality of molds, on the mold holder; a moving step of moving a mold disposed to the left of the spacer mold and a mold disposed to the right of the spacer mold around the spacer mold, the spacer die is a mounting member to which an insert die for performing the bending process on the workpiece is removably mounted, The moving step includes: a first step of moving a mold disposed on the left side of the spacer mold and a mold disposed on the right side of the spacer mold toward the spacer mold so as to come into close contact with the spacer mold; a second step of moving a mold disposed to the left of the spacer mold and a mold disposed to the right of the spacer mold in directions away from the spacer mold, respectively, to form spaces on the left and right sides of the spacer mold into which the inserting mold can enter, After the first step, the table is lowered relative to the workpiece; When the table reaches a first lowered position that is located a predetermined distance above the position where the workpiece is pressed, the table stops lowering, and then the second step is performed. After the second step, a mounting step of mounting the insert mold to the spacer mold is further provided, the insert die is positioned below the die holder in a state where it is attached to the spacer die, When the spacer mold is pulled up in accordance with the clamping operation of the mold holder, the insert mold attached to the spacer mold is also pulled up, and the upper surface of the insert mold comes into close contact with the lower surface of the mold holder. Press brake bending method.

10. The moving step includes: The method further includes a third step of moving a mold disposed on the left side of the insert mold and a mold disposed on the right side of the insert mold toward the spacer mold so that the molds are in close contact with the insert mold when the insert mold is attached to the spacer mold. The press brake bending method according to claim 9.

11. a bending process in which the table is lowered relative to the workpiece from the first lowered position to a bottom dead center, and then the table is raised relative to the workpiece to the first lowered position; and a removal step of removing the insert die from the spacer die by moving the insert die rearward after the workpiece is horizontally moved rearward. The press brake bending method according to claim 9.

12. The moving step includes: a fourth step of moving, after the removing step, a mold disposed on the left side of the spacer mold and a mold disposed on the right side of the spacer mold toward the spacer mold so as to come into close contact with the spacer mold, After the fourth step, the table is raised from the first lowered position relative to the workpiece. The press brake bending method according to claim 11.

13. The press brake a mold holding member for holding the plurality of molds and the spacer mold, and a movable body provided on the table so as to be movable in the left-right direction; The press brake bending method according to any one of claims 9 to 12.

14. The press brake An inserting die device is provided behind the table, which moves the inserting die between a mounting position where the inserting die is mounted to the spacer die and a retreat position where the inserting die is separated from the spacer die. The press brake bending method according to any one of claims 9 to 13.

15. The insert mold device is a spacer die coupled to the insert die and holding the insert die in the mounting position while the insert die is being mounted on the spacer die; The press brake bending method according to claim 14.

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