0001]The present invention, shearing method, shearing device, and to a shearing equipment.
BACKGROUND
[0002]Shearing, for example an automobile, railway vehicle, building materials, vessels, in the manufacture of metal parts for use, such as household appliances, cutting of the metal member, punched, punching, shaving is carried out for such trimming. Generally, shearing is performed by pushing the upper blade from the upper side to the lower blade is in contact with the member. In this case, the member plastically deformed between the upper and lower blades, and eventually breaks. In such shearing, affected portion of the work hardening due to plastic deformation may remain known member end surface after fracture. When carrying out such a flange-up as post-process, in part affected by the work hardening is sometimes cracks may occur.
[0003]
　Therefore, techniques for obtaining shearing surface having excellent flanging stretch while suppressing work hardening member during shearing have been proposed. For example, Patent Document 1, by appropriately setting the inclination angle of the punch blade by using numerical simulation, discloses a technique to obtain a shearing surface which is excellent in stretch flange formability. Further, Patent Document 2, by gradually increasing the clearance according to deviate from risk portion where it is determined based on a simulation of the stretch-flange cracking in a later step, a technique to obtain a shearing surface which is excellent in stretch flange formability Are listed.
CITATION
Patent Document
[0004]
Patent Document 1: JP 2011-88152 JP
Patent Document 2: JP 2016-87642 JP
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　However, shearing or more of plastically deforming the member, work hardening itself inevitable. Further, the fracture surface of the member which occurs along the surface connecting the upper and lower blades would traverse the area where work hardening occurs intensively. Thus, for example, be employed the technique described in Patent Documents 1 and 2 above, still the member end face after fracture retains the affected portion of work hardening, still the properties such as stretch flangeability there is room for improvement.
[0006]
　Accordingly, the present invention makes it possible to reduce the effect of work hardening in the member end face after fracture, and an object thereof is to provide new and improved shearing methods, shearing devices, and shear processing equipment .
Means for Solving the Problems
[0007]
　According to some aspects of the present invention, there is provided below.
[1] a plate-like by the action of shear forces in the thickness direction of the workpiece to a shearing process for breaking the workpiece,
　the clearance point of action in a plane direction perpendicular to the thickness direction of the workpiece with a step of starting to exert a shearing force to the workpiece,
　after starting exerting a shear force, a step of reacting a shear force to fracture surface on a workpiece is generated,
　the shearing force after starting exerting, until fracture surface on a workpiece is produced, according to the deformation in the thickness direction of the workpiece, the step of increasing the clearance
　including, shearing method.
[2] and the lower blade, and a the lower knife and the relatively movable upper blade in the thickness direction of the workpiece, a plurality of clearance of the lower blade and upper blade along the surface direction of the workpiece are different be carried out by the shearing device,
　the step of increasing the clearance of the plurality of shearing devices, from a small shearing device clearance, in the order of large shearing device clearance, by the action of shear forces on the workpiece
　go, shearing method according to [1].
[0008]
[3] and the lower blade abutting on the lower surface of the workpiece is carried out by one of the shearing device including an upper blade movable relative to the lower blade in a thickness direction of the workpiece,
　a step of abutting the lower blade on the lower surface of the workpiece,
　and moving the upper blade in the thickness direction until it abuts against the upper surface of the workpiece with the lower blade and the clearance along the surface direction of the workpiece ,
　the upper blade which abuts against the upper surface of the workpiece, the step of moving further the thickness direction of the workpiece to fracture surface on a workpiece occurs,
　contact with the upper surface of the upper blade the workpiece after, until fracture surface is generated, the step of increasing the clearance in accordance with the relative movement of the upper blade and lower blade in the thickness direction of the workpiece
　including, shearing according to [1] Method.
[0009]
[4] the lower blade is movable relative to the upper blade in the surface direction of the workpiece,
　the step of increasing the clearance, the lower blade according to the amount of movement of the upper blade from the upper blade comprising the step of separation, shearing method according to [3].
[5] the step of increasing the clearance described comprising the step of continuously increasing the clearance in accordance with the relative movement of the upper blade and lower blade in the thickness direction of the workpiece, [3] or [4] shear processing method.
[6] step of increasing the clearance described comprising the step of increasing the clearance stepwise in response to relative movement of the upper blade and lower blade in the thickness direction of the workpiece, [3] or [4] shear processing method.
[0010]
[7] step of increasing the clearance includes the step of increasing the clearance at a single timing determined in accordance with the relative movement of the upper blade and lower blade in the thickness direction of the workpiece, [3] or shearing method according to [4].
[8] Step of increasing clearance, if clearance is fixed to a predetermined value, the upper upper blade in the thickness direction of the workpiece until the fracture surface is generated from the contact with the upper surface of the workpiece is performed in the range of moving amount of more than 20% of the reference movement amount corresponding to the relative moving amount of the blade and lower blade, shearing method according to any one of [7] [3].
[9] the workpiece is a more tensile strength 270MPa of the steel sheet, shearing method according to any one of [8] [1].
[10] workpiece is the plate thickness of 0.2mm or more, or less of the steel sheet 2 mm, shearing method according to any one of [9] [1].
[0011]
[11] and the lower blade,
　is movable in the approaching separation direction with respect to the lower blade, in the direction perpendicular to the approaching direction of separation, the upper blade facing the lower blade with a clearance,
　the amount of movement approaching the direction of the upper blade Correspondingly, the clearance adjustment mechanism to increase the clearance
shearing device comprising a.
[0012]
[12] the lower blade is movable relative to the direction perpendicular to the approaching separation direction of the upper blade,
　the clearance adjustment mechanism on the lower blade according to the relative movement amount of the approaching direction of the upper blade and lower blade moved away from the blade, shear processing apparatus according to [11].
[13] clearance adjustment mechanism is continuously increased in accordance with the relative movement of the approaching direction of the upper blade and lower blade clearance, shear processing apparatus according to [11] or [12].
[14] clearance adjustment mechanism,
　　the direction of the relative movement of the upper blade and lower blade, the first inclined surface being movable integrally with the upper blade,
　　sliding contact with the first inclined surface, the relative movement direction of the upper blade and lower blade in a direction perpendicular to the, and the second inclined surface being movable integrally with the lower blade
　comprises,
　shearing device comprises a first inclined surface and the second inclined plane in a state in which no sliding contact, holding a clearance further comprising a clearance retaining mechanism, shear processing apparatus according to [13].
[0013]
[15] clearance adjustment mechanism in accordance with the movement of the approaching direction of the upper blade, the resilient means for providing a resilient force against the pressing force receiving said lower blade in a direction perpendicular to the approaching direction of the upper blade to the lower blade including, shear processing apparatus according to [13].
[16] clearance adjustment mechanism stepwise increasing clearance in accordance with the relative movement of the approaching direction of the upper blade and lower blade, shear processing apparatus according to [11] or [12].
[17] clearance adjusting mechanism increases the clearance of a single timing determined in accordance with the relative movement of the approaching direction of the upper blade and lower blade, shear processing apparatus according to [11] or [12].
[18] clearance adjusting mechanism increases the clearance in the range of more than 20% of the amount of movement of the reference movement amount corresponding to the relative movement amount of the upper blade and lower blade to processing end from the machining starting from [11] [ shearing device according to any one of 17.
[19] a transfer device for transferring a workpiece, arranged along the conveying path of the conveying device, a shearing installation comprising a plurality of shearing devices for performing by sharing the shearing against the workpiece ,
　each of the plurality of shearing devices, and the lower blade, is movable in the approaching separation direction with respect to the lower blade, in the direction perpendicular to the approaching separation direction, and a blade on opposing the lower blade with clearance,
　a plurality of shearing devices, toward the downstream from the upstream conveying path, are arranged such clearance becomes larger
　shearing equipment.
[0014]
　According to the present invention, during the shearing, by changing the direction of increasing the clearance, it is possible to reduce the influence of work hardening in the member end face after rupture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
FIG. 1 is a schematic sectional view showing a shearing apparatus according to an embodiment of the present invention.
The behavior of the operation and the workpiece shear processing apparatus shown in FIG. 2A] FIG. 1 is a diagram schematically showing.
The behavior of the operation and the workpiece shear processing apparatus shown in FIG. 2B] FIG. 1 is a diagram schematically showing.
The behavior of the operation and the workpiece shear processing apparatus shown in FIG. 2C] FIG. 1 is a diagram schematically showing.
In contrast to FIG 3A] FIG. 2A, the behavior of the operation and the workpiece in a conventional shearing device is a diagram schematically illustrating.
In contrast to FIG. 3B] FIG. 2B, the behavior of the operation and the workpiece in a conventional shearing device is a diagram schematically illustrating.
In contrast to FIG. 3C] FIG. 2C, the behavior of the operation and the workpiece in a conventional shearing device is a diagram schematically illustrating.
It is a schematic sectional view showing another example of the clearance adjustment mechanism in the embodiment of FIG. 4 the present invention.
Is a schematic cross-sectional view showing still another example of the clearance adjustment mechanism in the embodiment of FIG. 5A] present invention.
It is a schematic cross-sectional view showing still another example of the clearance adjustment mechanism in the embodiment of FIG. 5B] present invention.
6 is a schematic cross-sectional view showing still another example of a clearance adjusting mechanism in an embodiment of the present invention.
7 is a schematic cross-sectional view showing still another example of the clearance adjustment in an embodiment of the present invention.
8 is a graph for explaining the embodiment of the invention continuously increased the clearance.
9 is a graph for explaining an embodiment of the present invention gradually increasing the clearance.
[FIG. 10A] is a photograph showing an end surface shape of the workpiece after the break in the embodiment of the present invention.
[FIG. 10B] is a photograph showing an end surface shape of the workpiece after the break in the comparative example.
11 is a graph showing the average Vickers hardness of the end face of the workpiece after the break in the examples and comparative examples of the present invention.
Is a graph showing the hole expansion of the workpiece after the break in the examples and comparative examples of FIG. 12 the present invention.
13 is a graph for explaining another embodiment of the present invention gradually increasing the clearance.
14 is a graph showing an aperture ratio of the side bend test in Examples and Comparative Examples shown in FIG. 13.
15 is a graph for explaining a preferred embodiment of the present invention of increasing collectively at timing determined in accordance with the amount of movement clearance.
16 is a graph showing an aperture ratio of the side bend test in Examples and Comparative Examples shown in FIG. 16.
It is a diagram schematically showing the behavior of the operation and the workpiece shear processing apparatus when [FIG 17A] is increased collectively at a timing that is determined in accordance with the amount of movement clearance.
It is a diagram schematically showing the behavior of the operation and the workpiece shear processing apparatus when [FIG 17B] is increased collectively at a timing that is determined in accordance with the amount of movement clearance.
It is a diagram schematically showing the behavior of the operation and the workpiece shear processing apparatus when [FIG 17C] is increased collectively at a timing that is determined in accordance with the amount of movement clearance.
It is a diagram schematically showing the behavior of the operation and the workpiece shear processing apparatus when [Fig 17D] is increased collectively at a timing that is determined in accordance with the amount of movement clearance.
DESCRIPTION OF THE INVENTION
[0016]
　Hereinafter, with reference to the accompanying drawings, it will be described in detail an embodiment of the present invention. In the specification and drawings, components having substantially the same function and structure are a repeated explanation thereof by referring to the figures.
[0017]
　Figure 1 is a schematic sectional view showing a shearing device 1 according to an embodiment of the present invention. Referring to FIG. 1, shearing apparatus 1 according to the embodiment includes a die 2, and punch 3, and the holder 4, and an actuator 5a. The die 2, lower blade 21 is formed in contact with the lower surface of the plate-shaped workpiece 6. The punch 3, the upper blade 31 is formed. Punch 3 is driven by such as an electric motor or a hydraulic mechanism, not shown, is movable relative to the die 2 to the thickness direction of the workpiece 6 (toward and away from the direction of the upper blade 31 and lower blade 21). By punch 3 moves, the upper blade 31 from the state of being positioned above the workpiece 6 are brought into contact with the upper surface of the workpiece 6 as shown, pushed further into the workpiece 6 It is. In the course of the upper blade 31 is pushed into the workpiece 6, the fracture surface is generated between the lower blade 21 and upper blade 31, whereby the workpiece 6 parts punch 3 is pressed is cut off. Holder 4 is brought into contact with the upper surface of the workpiece 6, for holding the workpiece 6 between the die 2. Actuators 5a, for example an electric motor or a hydraulic mechanism, and the like. The actuator 5a is coupled to the die 2, the plane direction of the die 2 the workpiece 6, i.e. is moved in a direction perpendicular to the thickness direction of the workpiece 6.
　In the above description, have been described as the upper blade 31 is moved relative to the approaching separation direction with respect to the lower blade 21 is not limited thereto, the upper blade 31 is fixed, the lower blade 21 is moved relative At best, the upper blade 31 and lower blade 21 may be moved relative to each other.
[0018]
　Here, the surface direction of the workpiece 6 (a direction perpendicular to the approaching separation direction of the upper blade 31), the upper blade 31 is opposed to the lower blade 21 with clearance C. Actuator 5a is by moving the die 2 in the surface direction of the workpiece 6 can be moved toward or away from the lower blade 21 with respect to the upper blade 31. Clearance C is reduced when the lower blade 21 approaches the upper blade 31, the clearance C enlarges the lower blade 21 is spaced from the upper blade 31. Actuators 5a, after the upper blade 31 comes into contact with the upper surface of the workpiece 6, until fracture surface on a workpiece 6 is generated, increases the clearance C in accordance with the amount of movement of the upper blade 31. Specifically, the actuator 5a, depending on the amount of movement in the thickness direction of the workpiece 6 of the upper blade 31 to separate the lower blade 21 from the upper blade 31. In this manner, in the present embodiment, the actuator 5a serves as a clearance adjustment mechanism. The actuator 5a may be continuously separated from the wafer 31 to lower blade 21 according to the amount of movement of the upper blade 31, or the lower blade 21 stepwise in accordance with the movement amount of the wafer 31 it may be spaced from the upper blade 31. The actuator 5a may also be separate the lower blade 21 by a single timing determined according to the amount of movement of the thickness direction of the upper blade 31 from the upper blade 31 by a predetermined distance.
[0019]
　FIGS. 2A 2C are diagrams illustrating the operation and behavior of the workpiece 6 in the shearing device 1 shown in FIG. 1 schematically.
[0020]
　FIG 2A, the upper blade 31 is in contact state is shown in the top of the workpiece 6. At this time, the clearance C is c 0 is set to. In the following description, the movement quantity H of the upper blade 31 at this time (the amount of movement of the thickness direction of the workpiece 6) is zero. From the state shown in Figure 2A, by further moving the upper blade 31 starts pushed the workpiece 6, and plastic deformation of the material in the interior of the workpiece 6, work hardening and begin with it. In this case, work hardening of the material, the area R along a plane connecting the lower blade 21 and upper blade 31 1A to focus on.
　In the present embodiment, the state of FIG. 2A, with clearance of action point in a plane direction perpendicular to the thickness direction of the workpiece 6, step (processing start) to start acting shear forces on the workpiece 6 It corresponds to.
[0021]
　The Figure 2B, there is shown a state of being pressed into the workpiece 6 by the upper blade 31 is further moved from the state shown in Figure 2A. At this time, movement quantity H of the upper blade 31 is h 1 is. After the state shown in FIG. 2A, the actuator 5a moves the die 2 by the lower blade 21 is spaced from the upper blade 31, the clearance C is c 0 from c 1 is increased to. Work hardening of the material inside the workpiece 6, the region R 1B is occurring on. Region R 1B , the region R 1A as compared to having a flared shape at the lower surface side of the workpiece 6.
[0022]
　The Figure 2C, moves the upper blade 31 is further from the state shown in Figure 2B, it is more deeply pressed into the workpiece 6 states is shown. Movement quantity H of the upper blade 31 is h 1 larger h than 2 is. In this case, the fracture surface 61 is generated in the workpiece 6. After the state shown in Figure 2B, the actuator 5a is moved further the die 2 by the lower blade 21 is further spaced apart from the upper blade 31, the clearance C is c 1 from c 2 to have increased further. Work hardening of the material inside the workpiece 6, the region R 1C is occurring on. Region R 1C , the region R 1A as compared to having a further broadened shape at the lower surface side of the workpiece 6.
　In the present embodiment, the state of FIG. 2B and 2C, after starting exerting a shear force, a step of reacting a shear force to fracture surface on a workpiece 6 is generated (processing end), shearing force after starting to exert a, until fracture surface 61 on a workpiece 6 is generated, which corresponds to the step in accordance with the deformation in the thickness direction of the workpiece 6, to increase the clearance.
[0023]
　Here, as shown in FIG. 2C, fracture surface 61 of the workpiece 6, the region R work hardening occurs 1C generates across. Therefore, the end face of the workpiece 6 after fracture would region affected by the work hardening remains. However, as will be described later, in this embodiment, by the clearance C is increased in accordance with the movement quantity H of the wafer 31 during shearing, work hardening occurs dispersed in wider than the conventional area . Therefore, in the present embodiment, the influence of work hardening at the end face of the workpiece 6 after fracture is reduced than before.
[0024]
　3A-3C in comparison with Figure 2C from Figure 2A, a diagram schematically showing the operation and behavior of the workpiece 6 in a conventional shearing device. In the conventional example shown, throughout the shearing clearance C is c 2 is fixed (the
[0025]
　In the state shown in FIG. 3A, work hardening of the material inside the workpiece 6 region R 2A is occurring on. Region R shown in FIG. 2A 1A as with the region R 2A is a region along the plane connecting the upper blade 31 and lower blade 21.
[0026]
　In the state shown in FIG. 3B, work hardening of the material inside the workpiece 6 region R 2B is occurring on. The region R shown in FIG. 2B 1B is had a widened shape on the lower surface side of the workpiece 6, the region R shown in FIG. 3B 2B no such spread on.
[0027]
　In the state shown in FIG. 3C, work hardening of the material inside the workpiece 6, the region R 2C is occurring on. The region R shown in FIG. 2C 1C has been further have a flared shape at the lower surface side of the workpiece 6, the region R shown in FIG. 3C 2C without such spread in the region R 2C is relatively narrow region along the plane connecting the upper blade 31 and lower blade 21.
[0028]
　Here, the present embodiment shown in FIG. 2C, in between the conventional example shown in FIG. 3C, the clearance C when the fracture surface 61 is generated in the workpiece 6 are the same (c 2 for a) The end affected work hardening surface region of the workpiece 6 is also the same point that remains after breaking. However, the region R work hardening at break in the present embodiment has occurred 1C , the region R of the conventional 2C wider than. That is, in the present embodiment, work hardening occurs dispersed in a region wider than before. Accordingly, in the present embodiment, the effect of work hardening at the end face of the workpiece 6 after breaking can be reduced than conventionally.
[0029]
　Figure 4 is a schematic sectional view showing another example of the clearance adjustment mechanism in an embodiment of the present invention. Referring to FIG. 4, in this example, shearing apparatus 1 is provided with a linear cam mechanism 5b as the clearance adjustment mechanism. Linear cam mechanism 5b includes a first inclined surface 51 formed on the punch 3, and a second inclined surface 52 formed on the die 2. The first inclined surface 51, together with the upper blades 31 formed on the punch 3 can be moved in the thickness direction of the workpiece 6 integrally. The second inclined surface 52, in sliding contact with the first inclined surface 51, together with the lower blade 21 formed in the die 2 can move in the plane direction of the workpiece 6 integrally. The shearing device 1 further spring 22 which urges the die 2 to the punch 3 are provided in the surface direction of the workpiece 6. The spring 22 holds the clearance C when the first inclined surface 51 and the second inclined surface 52 is not in sliding contact, functions as a clearance retaining mechanism.
[0030]
　In the above example the movement, when the punch 3 is first inclined surface 51 by which to move in the thickness direction of the workpiece 6 comes into contact with the second inclined surface 52, the die 2 is in the plane direction of the workpiece 6 and, the lower blade 21 starts away from the upper blade 31. Thereafter, when the first inclined surface 51 and the punch 3 while the second inclined surface sliding contact continues to move in the thickness direction of the workpiece 6, the upper blade 31 continuously lower blade 21 with it go away from the. In this way, in the above example, the linear cam mechanism 5b are moved away continuously from the upper knife 31 the lower blade 21 in accordance with the amount of movement of the upper blade 31.
[0031]
　When using the linear cam mechanism 5b as the clearance adjustment mechanism, it is possible to change the clearance C by using the driving force of the punch 3, for example, faster equipment simplification and process can be achieved. In contrast, when using the actuator 5a described above as the clearance adjustment mechanism, it is possible to change the clearance C as an independent operation from the driving of the punch 3, for example, the way of change in the clearance C (change amount, rate of change, such as the start time point and an end point of change) can be arbitrarily adjusted.
[0032]
　5A and 5B are schematic cross-sectional view showing still another example of the clearance adjustment mechanism in an embodiment of the present invention.
　In the example described in FIG. 4, a high die 2 rigid to lower blade 21 is provided, by the linear cam mechanism 5b, by forcibly moved in a direction clearance changes had varying the clearance C.
　In contrast, in the present example, referring to FIG. 5A, the second shearing apparatus 1 includes a die body 2a, an elastic member 5c, the lower blade 21 of lower rigidity die body 2a, the elastic member 5c in by supporting and controls how relief of the lower blade 21 in a direction of varying the clearance.
[0033]
　In a state that allows movement of the direction of change in the clearance of the die body 2a, the elastic member 5c for supporting the die body 2a.
　Die body 2a is in the upper portion including a lower blade 21, the thickness in a direction clearance is changed is provided with a thinner thinner portion than other portions in the vertical direction.
　Elastic body 5c is in a state where the punch 3 is in contact with the workpiece 6, for supporting the thin portion of the at least die body 2a.
　Die body 2a and the elastic body 5c is not always required to be joined, it may be spaced apart during non action of shearing forces. The thickness of the thinner portion may be different in the vertical direction.
　Elastic 5c may be arranged in a state of continuous along the extending direction of the lower blade 21.
　Vertical length and the length of the clearance changed direction of the elastic member 5c is, for example, appropriately set on the basis of the modulus of Relevant and elastic bodies 5c of the arrangement of the holder 4.
[0034]
　Elastic body 5c is attached to such a wall, not shown on the opposite side of the die body 2a. By the pressing force in the surface direction of the workpiece 6 to the lower blade 21 receives the upper portion of the lower blade 21 is elastically deformed is elastically deformed in a direction in which the clearance is changed. Elastic body 5c is an elastic force opposing the pressing force received by the lower blade 21 from the direction perpendicular to the surface direction of the workpiece 6, it gives the die body 2a including the lower blade 21. Thus, with the pressing force in the circumferential direction of the workpiece 6 that acts on the lower blade 21 is increased gradually, while the upper portion of the die body 2a being elastically deformed is supported by the elastic member 5c which is elastically deformed gradually it moves in the direction of the pressing force in the circumferential direction of the workpiece 6.
　Incidentally, it may be configured that the die body 2a does not have the thin part. In this case, the entire die body 2a, mounted movably along the surface direction of the workpiece 6, the elastic member 5c, will be supported in a state that allows movement of the die 2. With the pressing force in the circumferential direction of the workpiece 6 that acts on the lower blade 21 gradually increases, that the entire die body 2a is moved along the surface direction of the workpiece 6, the lower blade 21 gradually it moves in the direction of the pressing force in the circumferential direction of the workpiece 6.
[0035]
　In shearing apparatus 1, after the punch 3 including upper blade 31 comes into contact with the upper surface of the workpiece 6, further with the move in the thickness direction of the workpiece 6, the die 2 including the lower blade 21 pressing force in the circumferential direction of the workpiece 6, and specifically there is a case where the pressing force in a direction that the lower blade 21 is spaced from the upper blade 31 acts. Pressing force increases gradually with the movement of the upper blade 31. In this case, by providing an elastic force to the elastic member 5c as described above against the pressing force to the die body 2a, it is possible to continuously increase the clearance C in accordance with the amount of movement of the upper blade 31.
[0036]
　Incidentally, in this example, the initial thickness (if there is no workpiece 6 or the thickness of the case of the upper blade 31 is not in contact with the workpiece 6,) and the characteristics of the elastic body 5c of the elastic member 5c is the initial value c of the clearance C 0 is determined according to. Further, properties such as elastic modulus of the elastic member 5c (Young's modulus) is determined according to the appropriate rate of increase in the clearance C with respect to the movement quantity H of the upper blade 31.
　Further, instead of the elastic member 5c, it may be used a mechanical resilient means utilizing coil springs or air springs. For example, a support portion for supporting the lower blade 21 on the rear surface of the lower blade 21 is provided, after further cam mechanism for driving with the movement of the support portion, the link mechanism or the like is provided, the cam mechanism and the link mechanism is driven by a predetermined amount, the coil springs, by the action of compressive force to the air spring, may be given elastic force against the pressing force of the lower blade 21 to die body 2a.
[0037]
　Figure 6 is a schematic sectional view showing still another example of a clearance adjusting mechanism in an embodiment of the present invention. Referring to FIG. 6, in this example, the punch 3 in the standby state is located at the position indicated by the solid line in FIG. Punch 3, when in the position indicated by the solid line in FIG. 6, when viewed from the normal direction of the workpiece 6, the upper blade 31 of the punch 3 is positioned in the existence region of the die 2.
　Then, before the punch 3 starts descending, the same time as starting the descent, or the punch 3 retreats against the die 2 at any timing after the start of the descent, the punch 3 of the workpiece 6 Upon reaching the surface, the punch 3 is positioned at the position indicated by two-dot chain line in FIG. 6. When the punch 3 is in the position indicated by the two-dot chain line in FIG. 6, the punch 3 is the clearance C = c 0 is in contact with the upper surface of the workpiece 6 in a state having a.
　That is, in the standby state, the punch 3 may be waiting at any position, the punch 3 is driven, and at the same time or arriving before reaching the surface of the workpiece 6, the punch 3 and the die 2 is the clearance C = c 0 may be the movement of the punch 3 is completed from the standby state so that the position can be secured.
　In FIG. 6, with respect to the die 2, the punch 3 is explained in the form of moving, the movement of the die 2 and the punch 3 is not limited as long as including the case where it is the relative movement. For example, even when the die 2 is moved relative to the punch 3 may be a case where both the die 2 and the punch 3 moves.
[0038]
　Figure 7 is a schematic sectional view showing still another example of the clearance adjustment in an embodiment of the present invention. Referring to FIG. 7, in this example, shear processing equipment 7, transfer device 8 and shearing device 1A comprising a shearing device 1C from shearing device 1A which are arranged along the conveying device 8, shearing device 1B, are shared by shearing device 1C, for machining of the workpiece 6. In the present embodiment, each of the shearing device 1A, 1B, the 1C, the clearance adjusting mechanism is not is provided.
　Conveying device 8, and a robot arm, it is constructed from the belt conveyor or the like, transporting the workpiece 6 from the upstream in the order of shearing device 1C from shearing device 1A toward the downstream.
　In shearing device 1A, clearance C = c 0 is set to. In shearing device 1B, a large clearance C = c than the clearance of the shearing device 1A 1 is set to. In shearing device 1C, a large clearance is C = c than the clearance of the shearing device 1B 2 is set to.
[0039]
　By shearing device 1A, the workpiece 6 clearance C = c 0 , depression depth (the amount of movement of the upper blade 31 and lower blade 21 in the thickness direction of the workpiece 6) the pressing force in the state of H = 0 allowed to act. Hardening region R shown in FIG. 2A in this state 1A When occurs, the transfer device 8 to move the workpiece 6 to shearing apparatus 1B, the shearing device 1B, the workpiece 6, shown in Figure 2B clearance C = c 1 , depression depth H = h 1 processed to. Finally, the transfer device 8 to move the workpiece 6 to shearing apparatus 1C, the shearing device 1C, the clearance C = c shown in FIG. 2C the workpiece 6 2 , depression depth H = h 2 working up to. That is, in the present embodiment, a plurality of shearing devices 1A, 1B, 1C are toward the downstream from the upstream conveying path, it is arranged such clearance increases.
　In the above example, shearing equipment, three shearing device 1A, 1B, has been illustrated as comprising 1C, shearing equipment may be provided with two or more than three of the shearing device. In the case with a shearing device three or more, shearing device clearance C = c set to 1A 0 , shearing device clearance C = c set to 1B 1 , the clearance C that is set in shearing device 1C C = 0While maintaining the may be subjected to processing other sites in the workpiece 6.
[0040]
　Thus even with a shearing device 1C of a plurality of shearing devices 1A, with clearance of action point in a plane direction perpendicular to the thickness direction of the workpiece 6, exerting a shearing force to the workpiece 6 a step of starting the after starting to exert a shear force, a step of reacting a shear force to the fracture surface 61 is generated in the workpiece 6, after starting exerting a shear force, the object to be until fracture surface in the workpiece is generated, it can be carried out according to the deformation in the thickness direction of the workpiece 6, a step of increasing the clearance, the. Therefore, it enjoys the same operation and effects as described above.
[0041]
　Incidentally, examples of the clearance adjustment mechanism in the embodiment of the present invention is not limited to the above example. For example, the clearance adjustment mechanism, a plurality of or from a die 2 replaceable during shearing. In this case, a plurality of die 2 corresponding to different clearances C, by using sequentially replaced in accordance with the movement quantity H of the upper blade 31, it is possible to change the clearance C stepwise. The initial value of the clearance C (clearance c shown in FIGS. 2A 0 and end value) (clearance c shown in FIG. 2C 2 2 types of die 2 corresponding to),
[0042]
　It has been described an embodiment of the present invention. The configuration of the shearing device as shown in the sectional view of FIG. 1 may not necessarily common to the whole of the shearing device. In other words, shearing device according to this embodiment, in some shearing portion, the clearance adjustment mechanism (actuator 5a, such linear cam mechanism 5b) as described above while is provided, in other parts of the shearing parts is not provided clearance adjustment mechanism, thus may be one clearance is secured. More specifically, for example, may be the clearance adjustment mechanism is disposed stretch-flange crack is limited to easily curved portion occurs.
Example
[0043]
　Next, a description will be given of an embodiment of the present invention. Incidentally, in common with the embodiments described below, the workpiece is a steel plate of a tensile strength 615MPa, thickness is 1 mm. Furthermore, shearing is piercing using a punch having a diameter of 10 mm. The die to prepare 12 kinds of inner diameter of the hole portion changes at 0.025mm increments from 10.1mm to 10.4 mm, while sequentially replaced in accordance with the place to be described with reference to FIGS. 8 and 9 below Shear processing was carried out.
[0044]
　Figure 8 is a graph for explaining the embodiment of the invention continuously increased the clearance. In the graph shown in FIG. 8, a clearance C of Example 7 from Example 1, the relationship between the movement quantity H of the upper blade is shown. In the description of the following examples, the clearance C is described as a percentage of the thickness t (C / t). In each embodiment, although the clearance C by replacement of the die is increased by 0.0125mm increments from 0.05mm to 0.2 mm, in this case C / t from 5% to 20% increase at 1.25% increments It will be. In the description of the following examples, movement quantity H, the reference movement amount H _ref ratio (H / H for _ref described in). Here, the reference movement amount H _ref is a workpiece similar to Example, when sheared to secure the clearance to a maximum value (C / t = 20%) , the movement quantity H of the fracture surface is generated corresponding. Reference movement amount H _ref is measured by a test that is performed in advance, it is used as an index for control of the clearance C in common to each embodiment.
[0045]
　In the embodiments depicted, H / H _ref a predetermined value from 0 (Example 1, 10%, 20% in Example 2, 40% in Example 3, 60% in Example 4, Example 5 in 80%, 90% in example 6, until reaching the embodiment example 7 100%), quasi-continuous by sequentially replacing the 12 kinds of die above, C / t is between 5% to 20% It is to be increased. H / H _ref after has reached a predetermined value, while maintaining the C / t 20%, continued movement of the upper blade up to the fracture surface on a workpiece is produced.
[0046]
　Figure 9 is a graph for explaining an embodiment of the present invention gradually increasing the clearance. In the graph shown in FIG. 9, the clearance and C (C / t) in Examples 4 and 4s, the moving amount of the upper blade H (H / H _ref relationship between) are shown. The graph of the fourth embodiment is identical to that shown in FIG. Example 4s, the range of moving amount H of the same level as in Example 4, are C / t is increased from 5% to 20% by sequentially replacing the die. However, in Example 4s, by using only four of the 12 kinds of the die of the clearance C is in increments 0.0375Mm (i.e., at C / t 3.75% increments) changed stepwise It is way.
[0047]
　10A and 10B are photographs showing the end surface shape of the workpiece after the break in the examples and comparative examples of the present invention. The FIG. 10A, the end surface shape of the workpiece after the break in the embodiment 6 shown in FIG. 8 is shown above. The FIG. 10B, a workpiece similar to the embodiment, the maximum value of the clearance in the comparative example sheared (C / t = 20%) to be fixed (Comparative Example 1), after the breaking of the workpiece edge shapes are shown. As shown in these pictures, between Comparative Example 1 and Example 6, there was no significant difference in the end surface shape of the workpiece after the break. Similarly for Examples 5 and 7 from Example 2, there was no significant difference in the end surface shape of the workpiece after the break between the Comparative Example 1. Only Example 1, was observed a change in some edge shapes in comparison with Comparative Example 1, which will be described later.
[0048]
　Figure 11 is a graph showing the average Vickers hardness of the end face of the workpiece after the break in the examples and comparative examples of the present invention. In each instance, hardness, cut in a direction intersecting the end surface of the workpiece after the break, the measurement points of 14 points are arranged in the thickness direction of the workpiece at a position 80μm from the end face, Vickers It was determined by performing hardness test (JIS Z 2244). Incidentally, the points near the end surface of the workpiece to be observed in FIGS. 10A and 10B, the measurement point of the Vickers hardness test. The graph of FIG. 11, the average value at all the measurement points of the measured values of the Vickers hardness test in each Example (Hv _ave have) are shown.
[0049]
　Referring to the graph, in all of Examples 7 and Example 4s from Example 1, Hv _ave value of is less than the comparative example 1, work hardening at the end face of the workpiece after the break in each of the embodiments it can be seen that the impact is reduced. On the other hand, when comparing the examples, Hv _ave the value of particularly small, the clearance C is continuously increased, and an increase in the clearance C is H _ref run in the range of moving amount H which corresponds to 20% -80% It was the case (example 2 from example 5) to be. As for the first embodiment, it is considered that in order to change a slight edge shapes in comparison with Comparative Example 1 and other examples as described above has occurred, the hardness was slightly greater than in other embodiments .
[0050]
　Figure 12 is a graph showing the hole expansion of the workpiece after the break in the examples and comparative examples of the present invention. In each instance, hole expansion, the material to be processed which has been piercing with a punch having a diameter of 10mm as described above, was determined by performing a hole expanding test (JIS Z 2256). In the graph of FIG. 12 is index widened hole measured by hole expansion test in each Example (lambda) is shown.
[0051]
　Referring to the graph, in all of Examples 7 and Example 4s from Example 1, the value of λ is greater than Comparative Example 1, the hole expansion of the workpiece after breakage is improved in each example it can be seen that is. On the other hand, when comparing the examples, the value of λ is particularly large, the clearance C is continuously increased, and an increase in the clearance C is H _ref runs in the range of moving amount H which corresponds to 20% -80% It was the case (examples 2 to 5) that. As for the first embodiment, in order to change a slight edge shapes as compared with the comparative example and other embodiments as described above occurs, hole expansion is thought to have slightly lower than the other embodiments .
[0052]
　Figure 13 is a graph for explaining another embodiment of the present invention gradually increasing the clearance. In the graph shown in FIG. 13, the clearance between C (C / t) in Examples 8 and 9, the movement amount of the upper blade H (H / H ref relation between) are shown. Example 8 is an example in which gradually increasing the clearance C, after starting the shearing of the initial value of C / t as 5% H / H ref is 16%, 32%, and 48% at each C / t are exchanging die to increase in 3.75% increments. Thus, C / t increases in four steps from 5% of the initial value to 20% of the maximum value. Example 9 is an example in which likewise increased the clearance C stepwise as in Example 8, H / H ref is 32%, by exchanging the die when 64% and 96% C / and more slowly increase the t.
[0053]
　Figure 14 is a graph showing an aperture ratio of the side bend test in Examples and Comparative Examples shown in FIG. 13. It should be noted that the side bend test, Yoshida, outside five, "stretch flange formability of evaluation methods and measures technology", Nippon Steel Technical Report, Nippon Steel Corporation, 2012, No. 393, p.18-24 It is described in detail in. FIG 12, Examples 8 and 9 shown in FIG. 11, as well as in Comparative Example 1 was sheared by fixing the clearance to a maximum value (C / t = 20%), the aperture ratio of the side bend test It is shown. Referring to the graph, even aperture ratio In any of Examples 8 and 9 are exceeded Comparative Example 1, it can be seen that the stretch flangeability is improved in both embodiments. On the other hand, a comparison of Example 8 and Example 9, the aperture ratio is larger was Example 9 with increased C / t more slowly.
[0054]
　Here, in Example 7 from Example 1 described above, an increase in the clearance C is H _ref in Examples 6 and 7 is performed in the range of moving amount H of greater than 80% of the measurement of the Vickers hardness test although improvement in value and hole expansion ratio is observed, improvements width example 2 results in a somewhat smaller as compared with example 5 was observed. In contrast, between Example 8 and Example 9, an increase in the clearance C is H / H _ref than Example 8 ended with = 48%, an increase in the clearance C is H / H _ref = 96% in towards the end of the example 9 it was shown to be improved width of the aperture ratio is high. This results, depending on the characteristics required for the workpiece after shearing, the step of increasing the clearance C H _ref not always better to run in the range of 80% or less of the movement quantity H of, rather H ref If it is better to run to the extent of the movement quantity H of greater than 80% can be said to have been shown to also.
[0055]
　Figure 15 is a graph for explaining an embodiment of the present invention was increased by a single timing determined according to the relative movement amount of clearance. In the graph shown in FIG. 15, Comparative Example 2, Example 10, the clearance C (C / t) in Examples 11 and 12, the movement amount of the upper blade H (H / H _ref relationship with) shown It is.
　In Comparative Example 2, C / t is fixed a die to increase to 20% of the maximum value from the beginning.
　In Example 10, H / H ref of 32% of the time, C / t are exchanging die so as to increase up to 20% of the maximum value.
　On the other hand, in Example 11, H / H ref with 64% of the time, are exchanging die so C / t increases from 5% to 20%.
　Further, in Example 12, H / H _ref at the 96% timing, are exchanging die so C / t increases from 5% to 20%.
[0056]
　Figure 16 is a graph showing an aperture ratio of the side bend test in Example 12 and Comparative Example 2 to Example 10 shown in FIG. 15. Figure 16 is in Example 12 Comparative Example 2 and Example 10 shown in FIG. 15, the aperture ratio of the side bend test is shown. Referring to FIG. 16, in Comparative Example 2, although the opening ratio is as low as 46%, H / H becomes the timing of the die exchange _ref A large, an opening ratio gradually increases, Example in 12, the aperture ratio is greatly improved.
[0057]
　As shown in Examples 10 to Example 12, the aperture ratio of the side bend test is improved is assumed due to the following findings.
　First, as shown in FIG. 17A, initially processed by the upper blade 31 of the punch 3, the clearance C = c 0 machining of the workpiece 6 is started in the state of work hardening during the upper blade 31 and lower blade 21 region R 3A arises. As it is, the upper blade 31 is lowered, as shown in FIG. 17B, work hardening region R on the workpiece 6 3B is enlarged.
[0058]
　Further, the upper blade 31 is lowered, as shown in FIG. 17C, most work hardening of advanced region R 3C becomes immediately before the next, the fracture surface occurs. At this time, when retracting the lower blade 21 of the die 2, as shown in FIG. 17D, the fracture surface 61 connecting the upper blade 31 and lower blade 21, the region R work hardening occurs 3C instead, work hardening to reach occur not area.
　Thus, since work hardening region on the end portion of the workpiece 6 is hardly caused, workpiece 6 after processing, areas not affected by the work hardening becomes fractured surface, the aperture ratio increases.
[0059]
　The above results, as an example of increasing the clearance C in accordance with the moving amount H, continuously clearance C in accordance with the moving amount H, or stepwise not only example to increase, in accordance with the moving amount H determined examples of increasing the clearance C at a single timing to be also be said to have been shown to be effective to reduce the effects of work hardening in the member end face after rupture. However, depending on the timing of increasing the clearance C, a sufficient effect can sometimes not be obtained as in Examples 10 and 11, to predetermine the appropriate timing according to the movement amount H by a test or the like there is a need advance.
　Incidentally, as can be seen from FIG. 16, the timing H / H becomes die replacement _ref is, as the aperture ratio is improved the closer just before fracture surface 61 occurs. Therefore, the best timing, at the timing immediately before the fracture surface 61 occurs, to increase the clearance C is estimated to be.
[0060]
　Examples as described above, the present invention, it reduces the effect of work hardening at the end face of the workpiece after the break, it is effective to improve the workability of such spread holes in the post-processing It was shown.
[0061]
　In the above embodiment, when the step of increasing the clearance C is moving amount H is zero, that is, the upper blade is started immediately after contact with the upper surface of the workpiece, the movement quantity H is the step from the time it becomes a large predetermined value than 0, i.e. the upper blade may be started from the time of the course which is to some extent pushed into the workpiece.
[0062]
　In the above embodiment, a steel plate of a tensile strength 615MPa was conducted shearing as the workpiece, according to the findings of the present inventors, a workpiece in which the invention may be implemented more effectively, the tensile above strength 270 MPa, a relatively high strength steel sheet. The reason is that the behavior of the workpiece as described as an embodiment of the present invention described above, but is obtained by assuming that the ductile fracture cracks generated during shearing strength is local deformation at low steel because of its excellent performance, it is because such a ductile fracture crack is less likely to occur. According to the findings of the present inventors, if for example a tensile strength 980MPa or more high strength steel sheet, because the ductile fracture cracks stable during shearing, the present invention can be effectively implemented.
[0063]
　Further, in the above embodiment, the plate thickness is carried out shearing a steel plate 1mm as the workpiece, according to the findings of the present inventors, a workpiece in which the invention may be implemented more effectively, plate thickness of 0.2mm or more, or less of the steel sheet 2 mm. This is because if the thickness is too small, it the value of the clearance C becomes small with the, because the stable control of the clearance C due to the clearance adjustment mechanism becomes difficult. On the other hand, when the thickness is too large, often a change of edge shapes with that clearance C is changed occurs because the difficult to obtain the effect of reducing the effect of work hardening at the end face of the workpiece. The material of the workpiece, and the like depending on the shape of the shearing part, the plate thickness of 0.1mm or more, 4 mm or less, or the thickness is 0.05mm or more, even if: 8 mm, effective in the present invention It may be possible to implement. Further, the work material in the present invention is not necessarily limited to steel, other metal materials, or a plate such as aluminum alloy.
[0064]
　Having described in detail preferred embodiments of the present invention with reference to the accompanying drawings, the present invention is not limited to such an example. It would be appreciated by those skilled in the relevant field of technology of the present invention, within the scope of the technical idea described in the claims, it is intended to cover various changes and modifications , also such modifications are intended to fall within the technical scope of the present invention.
DESCRIPTION OF SYMBOLS
[0065]
　1, 1A, 1B, 1C ... shearing device, 2 ... die, 21 ... lower blade, 22 ... spring, 3 ... punch, 31 ... upper blade, 4 ... holder, 5a ... actuator, 5b ... linear cam mechanism, 5c ... elastic body, 51 ... first inclined surface, 52 ... second inclined surface, 6 ... workpiece, 61 ... fracture surface, 7 ... shearing equipment, 8 ... transporting device.

WE CLAIM

Wherein by the action of shear forces in the thickness direction of the plate-like workpiece and a shearing method for breaking a workpiece,
　with a clearance of working point the perpendicular plane direction in the thickness direction of the workpiece the the step of starting to exert a shearing force to the workpiece,
　after starting exerting the shear force, the step of reacting a shear force to the fracture surface the the workpiece occurs,
　the after starting to exert a shearing force, said until fracture surface on a workpiece is produced, in response to said deformation in the thickness direction of the workpiece, the step of increasing the clearance
　including, shear processing method.
[Requested item 2]
　And the lower blade, and a the lower knife to the thickness direction relative movable upper blades of the workpiece, wherein the lower blades and clearance of the upper blade along the surface direction of the workpiece are different be carried out by a plurality of shearing devices,
　the step of increasing the clearance of the plurality of shearing devices, from a small shearing device clearance, in the order of large shearing device clearance, shearing force said the workpiece gradually allowed to act,
　shearing method according to claim 1.
[Requested item 3]
　Wherein the lower blade abutting on the lower surface of the workpiece, wherein in the thickness direction of the workpiece is performed by one of the shearing device and a relatively movable upper blade against the lower knife,
　a step of abutting the lower blades on the lower surface of the workpiece,
　the said thickness of the upper blade with the lower knife and the clearance along the surface direction of the workpiece until it abuts against the upper surface of the workpiece a step of moving in a direction,
　the said upper blade in contact with the upper surface of the workpiece, said the step of moving in the thickness direction of the further the workpiece until fracture surface on a workpiece is produced,
　the upper after the blade is in contact with the upper surface of the workpiece, until the fracture surface is generated, the clearance in accordance with the relative movement of the upper blade and the lower knife in the thickness direction of the workpiece a step of increasing the
　containing, shearing method according to claim 1
[Requested item 4]
　The lower knife, said a movable relative to the upper blade in the surface direction of the workpiece,
　the step of increasing the clearance, the upper blades and the lower in the thickness direction of the workpiece depending on the relative movement of the blade a step of relatively separating the said lower blades and the upper blades
　include, shearing method according to claim 3.
[Requested item 5]
　Step of increasing the clearance in response to said relative movement of the upper blade and the lower knife in the thickness direction of the workpiece, the step of increasing the clearance continuously
　include, in claim 3 or 4 shear processing method described.
[Requested item 6]
　Step of increasing the clearance in response to said relative movement of the upper blade and the lower knife in the thickness direction of the workpiece, the step of increasing the clearance stepwise
contain, in claim 3 or 4 shear processing method described.
[Requested item 7]
　Step of increasing the clearance comprises a step of increasing the clearance at a single timing at which the determined in accordance with the relative movement of the upper blade and the lower knife in the thickness direction of the workpiece, claim shearing method according to 3 or 4.
[Requested item 8]
　Step of increasing the clearance, when the clearance is fixed to a predetermined value, the thickness of the workpiece from contact with the upper surface of the upper blade the workpiece until the fracture surface is generated It is performed in the upper blade and the range of more than 20% of the amount of movement of the reference movement amount corresponding to the relative movement amount of the lower knife in the direction, shearing according to claims 3 to any one of claims 7 Method.
[Requested item 9]
　The workpiece has a tensile strength of steel sheet of more than 270 MPa, shear processing method according to any one of claims 1 to 8.
[Requested item 10]
　It said workpiece is a plate thickness of 0.2mm or more, or less of the steel sheet 2 mm, shear processing method according to any one of claims 1 to 9.
[Requested item 11]
　And the lower blade,
　is movable in the approaching separation direction with respect to the lower knife, in a direction perpendicular to the approaching direction of separation, the upper blade opposed to the lower knife with a clearance,
　the amount of movement of the approaching direction of the upper blade and a clearance adjustment mechanism for increasing the clearance depending on the
shearing device comprising a.
[Requested item 12]
　The lower knife is movable relative to the direction perpendicular to the approaching separation direction of the upper blade,
　the clearance adjustment mechanism, the lower in response to relative movement of approach direction of the upper blade and the lower blade thereby separating the blade from the upper blade, shear processing apparatus according to claim 11.
[Requested item 13]
　The clearance adjustment mechanism continuously increase the clearance depending on the relative movement of the approaching direction of the upper blade and the lower knife, shear processing apparatus according to claim 11 or claim 12.
[Requested item 14]
　The clearance adjustment mechanism,
　　the relative movement direction of the upper blade and the lower knife, a first inclined surface which is movable integrally with the upper blade,
　　sliding contact with the first inclined surface, the upper blade and the lower blade in a direction perpendicular to the relative movement direction, and a second inclined surface which is movable integrally with the lower knife
　comprises,
　the shearing device includes a first inclined surface and the second inclined surface is in sliding contact in non state, further comprising a clearance retaining mechanism for holding said clearance, shearing apparatus according to claim 13.
[Requested item 15]
　The clearance adjustment mechanism in accordance with the movement of the approaching direction of the upper blade, a resilient means for providing a resilient force against the pressing force receiving said lower blade in a direction perpendicular to the approaching direction of the upper blade to said lower blade including, shearing apparatus according to claim 13.
[Requested item 16]
　The clearance adjustment mechanism, stepwise increase the clearance in accordance with the relative movement of the approaching direction of the upper blade and the lower knife, shear processing apparatus according to claim 11 or claim 12.
[Requested item 17]
　The clearance adjustment mechanism, the increase clearance single timing determined in accordance with the relative movement of the approaching direction of the upper blade and the lower knife, shear processing apparatus according to claim 11 or claim 12 .
[Requested item 18]
　The clearance adjusting mechanism increases the clearance in the range of the upper blade and at least 20% of the amount of movement of the reference movement amount corresponding to the relative movement amount of the lower knife to processing end from the machining start, claim 11 shearing apparatus according to any one of claims 17.
[Requested item 19]
　A conveying device for conveying a workpiece, arranged along the conveying path of the conveying device, wherein a shearing installation comprising a plurality of shearing devices for performing by sharing the shearing against the workpiece,
　each of the plurality of shearing devices, and the lower blade, is movable in the approaching separation direction with respect to the lower knife, in a direction perpendicular to the approaching direction of separation, the upper blade opposed to the lower knife with a clearance comprising a
　plurality of shearing devices, the following from the upstream of the conveyance path toward the downstream, is arranged such that the clearance becomes larger
　shearing equipment.