Press brake and metal mold positioning method for press brake

Abstract

To achieve correct positioning even if a special metal mold, of which a side face is not a perpendicular flat surface, is included in a plurality of upper metal molds arranged in an upper metal mold holder.SOLUTION: A press brake 1 comprises: an upper metal mold holder 6 which extends in a longitudinal direction, and in which a plurality of upper metal molds 3 are arranged; a first metal mold movement unit 7L and a second metal mold movement unit 7R that move the plurality of upper metal molds 3 in the longitudinal direction; and a control part 8 which executes positioning control of the plurality of upper metal molds 3. When a standard metal mold of which a side face is a perpendicular flat surface, and a special metal mold, of which a side face is not a perpendicular flat surface are included in the plurality of upper metal molds 3, the control part 8 divides the same into a standard metal mold group including only the standard metal mold and a special metal mold group including the special metal mold, and each divided group is pinched from left and right by a finger FL of the first metal mold movement unit 7L and a finger FR of the second metal mold movement unit 7R, and is positioned.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a press brake and a method for positioning a die for the press brake. [Background technology]

[0002] In conventional press brakes, the upper die is moved and positioned in the upper die holder on the upper table using an automatic tool changer (ATC). However, even if the upper die is positioned accurately before processing begins, once processing begins and pressure is applied by the press brake, the upper die will shift slightly due to the deflection of the upper and lower tables. If pressure is then applied repeatedly in this state, a gap that can be seen with the naked eye may appear between the upper dies.

[0003] Therefore, positioning has been performed by using fingers provided on a mold moving unit that moves the upper molds to pinch the multiple upper molds from the left and right and move them to accurate positions. This positioning involves an alignment operation in which fingers abut against the side surfaces of the upper molds and move them, and a moving operation in which fingers are inserted into insertion holes in the upper molds and move them (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6789356 Summary of the Invention [Problem to be solved by the invention]

[0005] However, among the upper dies, there are special dies called lug dies that have protrusions on the side of the die and the side is not a vertical flat surface. When multiple upper dies including such special dies are positioned by aligning or moving them together, there is a problem that the upper dies adjacent to the special dies are tilted and cannot be positioned accurately. [Means for solving the problem]

[0006] A first aspect of one or more embodiments is a press brake comprising: an upper die holder extending in the left-right direction and on which a plurality of upper dies are arranged; a first die movement unit and a second die movement unit having fingers inserted into insertion holes in the upper die and moving the plurality of upper dies in the left-right direction; and a control unit that moves the first die movement unit and the second die movement unit to control the positioning of the plurality of upper dies, wherein when the plurality of upper dies include standard dies with vertical, flat sides and special dies with non-vertical, flat sides, the control unit groups the plurality of upper dies into a standard die group including only the standard dies and a special die group including the special dies, and positions each group by clamping them from the left and right between the fingers of the first die movement unit and the fingers of the second die movement unit.

[0007] A second aspect of one or more embodiments is a die positioning method for a press brake, which includes an upper die holder extending in the left-right direction and on which multiple upper dies are arranged, and a first die moving unit and a second die moving unit having fingers inserted into insertion holes in the upper die and moving the multiple upper dies in the left-right direction, wherein if the multiple upper dies include standard dies with vertical, flat sides and special dies with non-vertical, flat sides, the multiple upper dies are grouped into a standard die group including only the standard dies and a special die group including the special dies, and each group is positioned by clamping it from the left and right between the fingers of the first die moving unit and the fingers of the second die moving unit. [Effects of the Invention]

[0008] According to one or more embodiments of the press brake and its die positioning method, accurate positioning is possible even if the multiple upper dies placed in the upper die holder include a special die whose side is not a vertical plane. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing the structure of a press brake according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing the shape of a mold with ears, which is an example of a special mold. [Figure 3] FIG. 3 is a diagram for explaining the movement of a finger provided in the second die moving unit of the press brake according to the first embodiment. [Figure 4] FIG. 4 is a flowchart showing the procedure of the positioning process for the upper die by the press brake according to the first embodiment. [Figure 5] FIG. 5 is a diagram for explaining a method for positioning an upper die by a press brake according to the first embodiment. [Figure 6] FIG. 6 is a diagram for explaining a problem in positioning the upper die using a conventional press brake. [Figure 7] FIG. 7 is a diagram for explaining a method for positioning an upper die by a press brake according to the second embodiment. [Figure 8] FIG. 8 is a diagram for explaining a method for positioning an upper die by a press brake according to the second embodiment. [Figure 9] FIG. 9 is a diagram for explaining a method for positioning an upper die by a press brake according to Modification 1 of the second embodiment. [Figure 10] FIG. 10 is a diagram for explaining a method for positioning an upper die by a press brake according to Modification 2 of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] Hereinafter, a press brake and a method for positioning a die therefor according to this embodiment will be described with reference to the drawings.

[0011] [Press brake structure] The structure of the press brake according to this embodiment will be described with reference to Figure 1. Figure 1 is a front view showing the structure of the press brake according to this embodiment. In Figure 1, "L" indicates the left direction, "R" indicates the right direction, "U" indicates the up direction, and "D" indicates the down direction. The front side of the paper in Figure 1 corresponds to the front direction, and the back side of the paper corresponds to the rear direction.

[0012] As shown in Fig. 1, the press brake 1 is a processing machine that performs bending processing on a workpiece W by pressing the workpiece W with an upper die 3 arranged on an upper table 2 and a lower die 5 arranged on a lower table 4. In particular, the press brake 1 includes an upper die holder 6, a first die moving unit 7L, a second die moving unit 7R, and a control unit 8.

[0013] The upper mold 3 is held so as to be movable in the left-right direction along the upper mold holder 6, and an insertion hole H is formed through the center of the width direction. The multiple upper molds 3 include standard molds with vertical, flat sides and special molds with non-vertical, flat sides.

[0014] A standard mold is a normal mold, and its left and right side surfaces are vertical planes, allowing adjacent molds to fit closely together. On the other hand, a special mold is, for example, a mold with lugs 21 as shown in Figure 2. This mold with lugs 21 has a protrusion 23 on the underside of one side, so one of the left and right side surfaces is not a vertical plane. In addition to this mold with lugs 21, special molds also include molds with slanted or uneven sides that prevent adjacent molds from fitting closely together, resulting in spaces between the molds.

[0015] The upper die holder 6 is provided at the lower end of the upper table 2, extends in the left-right direction, and has a plurality of upper dies 3 arranged therein. A plurality of upper die holders 6 are provided along the left-right direction at regular intervals, and detachably hold a plurality of upper dies 3.

[0016] The first mold moving unit 7L and the second mold moving unit 7R are mounted on guide rails attached to the rear of the upper table 2 so as to be movable in the left-right direction, and move the upper mold 3 between the upper mold holder 6 and the mold storage device 10. The first mold moving unit 7L is disposed on the left side of the multiple upper molds 3, and the second mold moving unit 7R is disposed on the right side of the multiple upper molds 3, and moves the multiple upper molds 3 by sandwiching them from the left and right.

[0017] The first mold moving unit 7L and the second mold moving unit 7R are each equipped with a servo motor as a moving actuator and an encoder as a position detector, so that the servo motor moves them left and right and the encoder detects their left and right positions.

[0018] The first die moving unit 7L and the second die moving unit 7R each have fingers FL, FR that are inserted into insertion holes H of the upper die 3, and move the multiple upper die 3 in the left-right direction. The fingers FL, FR are moved in the front-to-rear direction by driving an air cylinder, and are inserted into the insertion holes H from the rear of the upper die 3, as shown in FIG. 3. The first die moving unit 7L and the second die moving unit 7R insert the fingers FL, FR into the insertion holes H of the upper die 3, or abut the fingers FL, FR against the side surfaces of the upper die 3, and move the upper die 3 in the left-right direction along the upper die holder 6.

[0019] The control unit 8 moves the first mold moving unit 7L and the second mold moving unit 7R to control the positioning of the multiple upper molds 3. Specifically, when the multiple upper molds 3 include standard molds and special molds, the control unit 8 groups them into a standard mold group including only standard molds and a special mold group including special molds. Then, the control unit 8 positions each group by sandwiching it from the left and right between the fingers FL of the first mold moving unit 7L and the fingers FR of the second mold moving unit 7R.

[0020] The control unit 8 is configured by a computer having a memory, a processor such as a CPU (Central Processing Unit), and various interfaces. The memory and various interfaces are connected to the processor via a bus. The control unit 8 executes control to position the upper mold 3 by having the processor execute a program stored in the memory.

[0021] [Upper die positioning method] Next, a method for positioning the upper die 3 by the press brake 1 according to this embodiment will be described. FIG. 4 is a flowchart showing the processing steps for positioning the upper die 3. As shown in FIG. 4, in step S10, the control unit 8 groups the multiple upper dies 3 arranged in the upper die holder 6. Specifically, when the multiple upper dies 3 include standard dies and special dies, the control unit 8 groups them into a standard die group including only standard dies and a special die group including special dies.

[0022] Here, a specific example of grouping will be described with reference to Figure 5. Figure 5 shows multiple upper molds 3 arranged in an upper mold holder 6. As shown in Figure 5, the control unit 8 divides the molds into three groups, G1, G2, and G3. The molds G2a and G2c in group G2 are molds with lugs that have protrusions on their sides, and are therefore special molds whose sides are not vertically flat. Therefore, the control unit 8 divides the multiple upper molds 3 into groups at the positions of the side surfaces of the special molds G2a and G2c that are not vertically flat.

[0023] As a result, the molds are divided into three groups: standard mold groups G1 and G3, which include only standard molds, and special mold group G2, which includes special molds. In particular, by dividing the molds based on the position of the special molds, special molds G2a and G2c are placed at both ends of special mold group G2. Therefore, special molds are not placed within the special mold group, and tilting of the molds within the special mold group can be prevented.

[0024] In step S20, the control unit 8 positions each of the groups divided in step S10. Specifically, the control unit 8 positions each of the groups by sandwiching it from the left and right between the fingers FL of the first mold moving unit 7L and the fingers FR of the second mold moving unit 7R. Particularly in this embodiment, the control unit 8 positions each of the groups in order of length in the left-right direction.

[0025] 5, since group G1 is the longest in the left-right direction, the control unit 8 first positions group G1 by sandwiching it from the left and right between the fingers FL of the first mold moving unit 7L and the fingers FR of the second mold moving unit 7R. At this time, the control unit 8 positions the fingers FL of the first mold moving unit 7L and the fingers FR of the second mold moving unit 7R by abutting them against the side surfaces of the upper molds 3 located at the left and right ends of each group. Therefore, the control unit 8 positions the group G1 by performing an alignment operation in which the fingers FL abut against the side surface of the leftmost mold G1a of group G1 and the fingers FR abut against the side surface of the rightmost mold G1f of group G1.

[0026] This alignment operation is an operation to roughly correct the position of the upper die 3, and since if the position of the upper die 3 is significantly off, the fingers FL, FR cannot be inserted into the insertion holes H, the purpose is to move the upper die 3 to a position where the fingers FL, FR can be inserted into the insertion holes H. The alignment operation is mainly performed between multiple bending processes, when correcting the position of the die that has moved due to bending pressure, or before replacing or storing the die.

[0027] Thereafter, the control unit 8 similarly positions the second longest group G2, and finally the shortest group G3. Therefore, in the case of Fig. 5, the control unit 8 positions each group. When the positioning of all groups is completed in this manner, the positioning process of the upper mold 3 according to this embodiment is completed.

[0028] However, in Figure 5, the group is positioned so that it moves from the left and right toward the center, but positioning is merely moving each mold to the correct position, so it does not necessarily move it to the center. Therefore, if the entire group is moving to the right, the entire group is positioned so that it moves to the left.

[0029] [Effects of the first embodiment] As described above in detail, in the press brake 1 according to this embodiment, when the plurality of upper dies 3 includes both standard and special dies, the control unit 8 divides the dies into a standard die group including only standard dies and a special die group including special dies. The control unit 8 then positions each divided group by sandwiching it from the left and right between the fingers FL of the first die moving unit 7L and the fingers FR of the second die moving unit 7R. This allows accurate positioning even if the plurality of upper dies 3 arranged in the upper die holder 6 includes a special die whose side surface is not a vertical flat surface.

[0030] For example, as shown in Figure 6, if lug molds G2a and G2c are included in the mold layout, and they are positioned by sandwiching them from the left and right with fingers FL and FR, the molds G1f and G3a adjacent to the lug molds G2a and G2c will tilt and will not be positioned accurately. However, as explained in Figure 5, if the molds are divided into a standard mold group and a special mold group and each group is positioned by sandwiching them from the left and right with fingers FL and FR, the standard mold group and the special mold group can be positioned separately. Therefore, accurate positioning is possible even if a special mold is included.

[0031] Furthermore, in the press brake 1 according to this embodiment, the control unit 8 positions each group in order of the length in the left-right direction of the grouped members. As a result, since the group with the longer length has a larger overall deviation, by positioning the group with the larger deviation first, the remaining groups can be positioned accurately.

[0032] Furthermore, in the press brake 1 according to this embodiment, the control unit 8 divides and groups the multiple upper dies 3 at the position of the side of the special die that is not a vertical plane. This positions the special die at the end of the special die group, preventing the dies from tilting within the special die group and enabling the special die group to be accurately positioned.

[0033] Furthermore, in the press brake 1 according to this embodiment, the control unit 8 positions the fingers FL of the first die moving unit 7L and the fingers FR of the second die moving unit 7R by abutting them against the side surfaces of the upper die 3 located at both the left and right ends of each group. As a result, even if the amount of misalignment of the upper die 3 is large and the fingers FL, FR cannot be inserted into the insertion holes H, the group can be positioned using the fingers FL, FR.

[0034] [Second embodiment] A press brake and its die positioning method according to this embodiment will be described below with reference to the drawings. In the drawings, identical parts are designated by the same reference numerals, and detailed descriptions will be omitted. In the first embodiment, the groups were positioned in descending order of length, but in this embodiment, the special die group is positioned first, which is different. The structure of the press brake 1 according to this embodiment is the same as that of the first embodiment, so detailed descriptions will be omitted.

[0035] [Mold positioning method] Next, a die positioning method using the press brake 1 according to this embodiment will be described. In this embodiment, the same processing as that in the flowchart shown in Fig. 4 of the first embodiment is performed, but only the positioning processing in step S20 is different. Therefore, only step S20 will be described, and descriptions of the other steps will be omitted.

[0036] In step S20, the control unit 8 positions each group divided in step S10. Specifically, the control unit 8 positions each group by sandwiching it from the left and right between the fingers FL of the first mold moving unit 7L and the fingers FR of the second mold moving unit 7R. In particular, in this embodiment, the control unit 8 first positions the special mold group among the divided groups.

[0037] 7, since group G2 is a special mold group, the control unit 8 first positions group G2 by sandwiching it from the left and right between the fingers FL of the first mold moving unit 7L and the fingers FR of the second mold moving unit 7R. At this time, the control unit 8 positions the group G2 by inserting the fingers FL of the first mold moving unit 7L and the fingers FR of the second mold moving unit 7R into the insertion holes H of the upper molds 3 located at the left and right ends of each group. Therefore, the control unit 8 positions the group G2 by performing a moving-up operation in which the fingers FL are inserted into the insertion hole H of the mold G2a at the left end of group G2 and the fingers FR are inserted into the insertion hole H of the mold G2c at the right end of group G2.

[0038] This approaching operation is an operation to move the upper die 3 to the correct position set in the processing program, and since it moves while performing a pinching operation from the left and right, it has the effect of eliminating gaps between the dies. The approaching operation is mainly performed between multiple bending operations, when correcting the position of a die that has moved due to bending pressure, or at the end of auto layout. Also, in the case of the lug die 21 shown in Figure 2, if the protrusion 23 is small, it may not be possible to insert the fingers FL and FR between the lug die 21 and the adjacent die. Even in such cases, the approaching operation of inserting the fingers FL and FR into the insertion hole H can be performed.

[0039] Furthermore, in the move-together operation, in order to eliminate gaps between the dies, the fingers FL and FR may be moved slightly from their normal positions toward the center of the group after positioning. For example, if the width of the dies is slightly smaller than the reference width due to tolerances, a gap may occur between the dies even when they are positioned in the normal position. Even in such cases, the gap can be eliminated by slightly moving the dies from the left and right after positioning. Because the amount of additional movement is small, the dies will not tilt even if they are moved from the left and right to sandwich a mold with tabs.

[0040] After this, the control unit 8 positions the group G1 adjacent to the special mold group G2. At this time, if the horizontal length of each group is longer than a predetermined value, the control unit 8 may divide the group and position it accordingly. For example, if the group G1 in FIG. 7 is longer than a predetermined value, it is divided at the position of mold G1e, and first positioned with respect to the portion from mold G1a to mold G1e. After this, it is again positioned with respect to the portion from mold G1a to mold G1f. In this way, when the length of the group is long, even performing the moving-together operation may not sufficiently eliminate the gap between the molds. Therefore, by dividing the group and performing the moving-together operation, the gap between the molds can be reliably eliminated.

[0041] Next, group G3 is positioned. However, since groups G1 and G2 located to the left of group G3 have already been moved to the correct positions, group G3 may be positioned relative to the left edge of the layout.

[0042] For example, as shown in Figure 7, first, the mold G1a at the left end of the layout and the mold G3a at the left end of the group G3 are positioned, and then the mold G1a at the left end of the layout and the mold G3e at the right end of the group G3 are positioned. This allows the entire group G3 to be positioned with respect to the left end of the layout. When the positioning of all groups is completed in this way, the positioning process for the upper mold 3 according to this embodiment is completed.

[0043] 7 illustrates the case where the group is moved to the left for positioning, but if the entire layout is shifted to the left, the group may be moved to the right for positioning. For example, as shown in FIG. 8, if the entire layout is shifted to the left, group G2 is a special mold group, so the control unit 8 first moves group G2 to the right, sandwiching it between fingers FL and FR. At this time, a gap is created between group G1 on the left, and the molds of group G3 on the right are pushed by the molds with lugs, causing them to tilt.

[0044] Next, the control unit 8 moves group G1, which is adjacent to the left of group G2, to the right and positions it, and finally positions group G3. In positioning group G3, the mold at the left end of the layout and the mold of group G3 are moved to the right and positioned, thereby correcting the tilt of the mold of group G3. In this way, the positioning of all groups is completed.

[0045] [Variation 1] 7 describes a case where the entire layout is shifted to the right, but in Modification 1, a case where the entire layout is shifted so as to spread out to the left and right from the center is described. As shown in FIG. 9, all of the molds are shifted so as to spread out to the left and right from the center position C. Since group G2 is a special mold group, the control unit 8 first positions group G2 so as to move it toward center position C.

[0046] Next, the control unit 8 positions the group G1, which is adjacent to the left side of the group G2, so that it approaches the center position C, and finally positions the group G3. In positioning the group G3, the mold at the left end of the layout and the mold of the group G3 are positioned so that they approach the center position C.

[0047] [Variation 2] While Fig. 7 describes a case where standard mold groups are located on the left and right of a special mold group, Modification Example 2 describes a case where special mold groups are located on the left and right of a standard mold group. As shown in Fig. 10, special mold groups G1 and G3 are located on the left and right of a standard mold group G2. Because groups G1 and G3 are special mold groups, the control unit 8 first positions group G1, and then positions group G3.

[0048] Next, the control unit 8 positions the group G2 relative to the left edge of the layout. First, the control unit 8 positions the mold G1a at the left edge of the layout and the mold G2a at the left edge of the group G2, and then the control unit 8 positions the mold G1a at the left edge of the layout and the mold G2g at the right edge of the group G2. Finally, the control unit 8 positions the mold G1a at the left edge of the layout and the mold G3d at the right edge of the group G3, completing the positioning of the entire layout.

[0049] [Effects of the second embodiment] As described above in detail, in the press brake 1 according to this embodiment, the control unit 8 positions the special tool group first among the divided groups. This positions the special tool group first to its normal position, allowing the remaining standard tool groups to be positioned accurately.

[0050] Furthermore, in the press brake 1 according to this embodiment, the control unit 8 inserts and positions the fingers FL of the first die moving unit 7L and the fingers FR of the second die moving unit 7R into the insertion holes H of the upper die 3 located at both the left and right ends of each group. This allows the dies to be moved by inserting the fingers FL and FR into the insertion holes H, so that the dies can be positioned in more accurate positions.

[0051] Furthermore, in the press brake 1 according to this embodiment, if the horizontal length of each group is longer than a predetermined value, the control unit 8 divides the group and positions it. As a result, since the positioning accuracy decreases as the group becomes longer, by dividing the group and positioning it, the positioning accuracy can be improved.

[0052] 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]

[0053] 1. Press brake 2 Upper table 3 Upper mold 4 Lower Table 5 Lower mold 6 Upper die holder 7L First mold transfer unit 7R Second mold moving unit 8 Control Unit 10. Mold storage device 21 Eared mold 23 Protrusion C center position FL, FR Finger G1, G2, and G3 groups H Insertion hole double work

Claims

1. an upper die holder extending in the left-right direction and on which a plurality of upper dies are arranged; a first die moving unit and a second die moving unit each having a finger inserted into an insertion hole of the upper die and moving the plurality of upper dies in a left-right direction; a control unit that moves the first mold moving unit and the second mold moving unit to perform positioning control of the plurality of upper molds, The control unit When the plurality of upper dies include a standard die having a vertically flat side surface and a special die having a non-vertically flat side surface, the upper dies are grouped into a standard die group including only the standard die and a special die group including the special die; Each group is positioned by being sandwiched from the left and right by the fingers of the first mold moving unit and the fingers of the second mold moving unit. Press brake.

2. The control unit positions each of the divided groups in order of length in the left-right direction.

2. The press brake of claim 1.

3. The control unit first positions the special mold group in each group.

2. The press brake of claim 1.

4. The control unit divides and groups the plurality of upper molds at positions of the side surfaces of the special mold that are not vertical planes. The press brake according to any one of claims 1 to 3.

5. The control unit positions the fingers of the first mold moving unit and the fingers of the second mold moving unit by bringing them into contact with side surfaces of the upper molds located at both left and right ends of each group. The press brake according to any one of claims 1 to 3.

6. The control unit inserts and positions the fingers of the first mold moving unit and the fingers of the second mold moving unit into the insertion holes of the upper molds located at both left and right ends of each group. The press brake according to any one of claims 1 to 3.

7. The control unit divides the group and positions it when the horizontal length of each group is longer than a predetermined value.

7. The press brake according to claim 6.

8. A die positioning method for a press brake, comprising: an upper die holder extending in the left-right direction and on which a plurality of upper dies are arranged; and a first die movement unit and a second die movement unit having fingers inserted into insertion holes of the upper die, and moving the plurality of upper dies in the left-right direction, When the plurality of upper dies include a standard die having a vertically flat side surface and a special die having a non-vertically flat side surface, the upper dies are grouped into a standard die group including only the standard die and a special die group including the special die; Each group is positioned by being sandwiched from the left and right by the fingers of the first mold moving unit and the fingers of the second mold moving unit. How to position the die for a press brake.

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