Chip powder reproduction device and chip powder reproduction method

Abstract

To reproduce a state of generation of chips in the time of press-cutting of a processing object material.SOLUTION: A chip reproduction device comprises: a preparation step of breaking a processing object material 1, a blade tip of a lower die 2 and a blade tip of a cutting blade 4 into a plurality of meshes 10-30, and setting the size of each mesh 10-30 to be equal to or less than the size of a chip 5 being a reproduction target; a pressing step of displacing the cutting blade 4 in such a state that the blade tip of the cutting blade 4 is brought into contact within a range of the mesh 10 on the front surface side of the processing object material 1; a measuring step of measuring main stress and plastic strain generated in the processing object material 1 in a process of cutting the processing object material 1 following the displacement of the cutting blade 4; a determining step of determining whether or not a measurement result in the measuring step is less than a threshold; and an acquiring step of acquiring an analysis image that reproduces the process of cutting the processing object material 1 following the displacement of the cutting blade 4 and acquiring an analysis image that reproduces the state where the chips are generated from the processing object material 1 when affirmative determination is made in the determining step.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a scrap reproduction device and a scrap reproduction method.

Background Art

[0002] For example, Patent Document 1 discloses an upper die and a lower die for press-cutting a workpiece to be pressed, and a pair of upper-die cutting blades and lower-die cutting blades provided on the upper die and the lower die for cutting the workpiece to be pressed along a planned cutting line to cut off an unnecessary portion from the product portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above Patent Document 1, although the generation mechanism of "scrap", which is one of the problems occurring in the process of press-cutting, has been clarified by experiments, it has not been possible to reproduce the state in which the scrap is generated.

[0005] In view of such circumstances, an object of the present invention is to provide a scrap reproduction device and a scrap reproduction method capable of reproducing the state in which scrap is generated when a workpiece is press-cut.

Means for Solving the Problems

[0006] The present invention relates to a chip reproduction device that sandwiches a workpiece between a lower die and an upper die and protrudes the workpiece from the end faces of the lower die and the upper die, and reproduces the state in which chips are generated when cutting is performed by bringing a cutting blade into contact with the workpiece, using the cutting edge of the upper corner of the end face of the lower die and the cutting edge of the cutting blade. The workpiece, the cutting edge of the lower die, and the cutting edge of the cutting blade are subdivided into a plurality of meshes, and a preparation step of setting the size of each mesh to be equal to or smaller than the size of the chips to be reproduced is performed. A pressing step of displacing the cutting blade while bringing the cutting edge of the cutting blade into contact within the range of the mesh on the surface side of the workpiece. A measuring step of measuring the principal stress and plastic strain generated in the workpiece in the process of cutting the workpiece as the cutting blade is displaced. A determination step of determining whether or not the measurement result in the measurement step is less than a threshold value. An acquisition step of acquiring an analysis image that reproduces the process of cutting the workpiece as the cutting blade is displaced and an analysis image that reproduces the state in which chips are generated from the workpiece when a positive determination is made in the determination step. It is characterized by executing these steps.

[0007] In this configuration, the sizes of the plurality of meshes set for the workpiece, the cutting edge of the lower die, and the cutting edge of the cutting blade are set to be equal to or smaller than the size of the chips to be reproduced, and the cutting edge of the cutting blade is brought into contact within the range of the mesh of the workpiece, that is, other than the end portion.

[0008] Thereby, an analysis image that reproduces the state in which chips are generated when the workpiece is cut by press cutting can be obtained.

[0009] In addition, the present invention sandwiches a workpiece between a lower die and an upper die and projects the workpiece from the end faces of the lower die and the upper die, and when cutting is performed with the cutting edge of the lower die's upper corner on the end face and the cutting edge of the cutting blade by bringing the cutting blade into contact with the workpiece, it is a cutting chip reproduction method for reproducing the state in which cutting chips are generated. The method includes a preparation process of subdividing the workpiece, the cutting edge of the lower die, and the cutting edge of the cutting blade into a plurality of meshes and setting the size of each mesh to be equal to or smaller than the size of the cutting chips to be reproduced; a pressing process of displacing the cutting blade while bringing the cutting edge of the cutting blade into contact within the range of the mesh on the surface side of the workpiece; a measurement process of measuring the principal stress and plastic strain generated in the workpiece during the process in which the workpiece is cut as the cutting blade is displaced; a determination process of determining whether or not the measurement result in the measurement process is less than a threshold value; and an acquisition process of acquiring an analysis image reproducing the process in which the workpiece is cut as the cutting blade is displaced and an analysis image reproducing the state in which cutting chips are generated from the workpiece when a positive determination is made in the determination process.

Effects of the Invention

[0010] According to the cutting chip reproduction device and the cutting chip reproduction method according to the present invention, it is possible to reproduce the state in which cutting chips are generated during press cutting of a workpiece.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

[0013] FIGS. 1 to 10 show an embodiment of a swarf reproduction device and a swarf reproduction method according to the present invention.

[0014] This swarf reproduction device is, for example, a computer (control device) that executes various programs by executing software, and executes a program for CAE (Computer Aided Engineering) analysis to reproduce the state in which swarf 5 is generated during press cutting of the workpiece 1.

[0015] Although not shown in detail, as is well known, the computer has a configuration in which a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory) are interconnected by a bus.

[0016] Connected to the bus via an input / output interface are at least an input unit (such as a keyboard, a mouse, a microphone, a touch panel, etc.), an output unit (such as a display, a speaker, etc.), a storage unit (such as a hard disk, a non-volatile memory, etc.), a communication unit (such as a network interface, etc.), and a drive for driving an external storage device (such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc.).

[0017] As shown in FIGS. 1 and 2, the press cutting device assumed in this swarf reproduction device sandwiches the workpiece 1 between a lower die (die) 2 and an upper die (pad) 3 and projects it from the end faces of the lower die 2 and the upper die 3, and is configured to cut with the cutting edge of the upper corner of the end face of the lower die 2 and the cutting edge of the cutting blade 4 by lowering the cutting blade (punch) 4 from above the workpiece 1.

[0018] The workpiece 1 is, for example, an automobile body panel or the like. The material of this body panel is, for example, a steel sheet, but in recent years, it has been aluminum. When such aluminum is press-cut, swarf tends to be generated.

[0019] Therefore, the present invention was devised for the purpose of establishing a technique for suppressing the generation of swarf 5 during press cutting in which the workpiece 1 is cut with the cutting edge of the lower die 2 and the cutting edge of the cutting blade 4.

[0020] The swarf reproduction device according to an embodiment of the present invention is equipped with a program for CAE analysis for reproducing the state in which swarf 5 is generated during press cutting, and has a configuration for executing the program.

[0021] Next, a method for reproducing the scrap 5 by the scrap reproduction device with the above configuration will be described with reference to the flowchart of FIG. 3.

[0022] In the CAE analysis, as shown in FIG. 1, a press cutting device 2D-modeled on the XY plane is used.

[0023] Regarding the analysis conditions, since the 2D model is analyzed in a plane strain state, the Z translation, X, and Y rotation components are assumed not to occur. In the workpiece 1, a range (for example, 2.3 mm) that affects the analysis result is modeled from the cutting edge of the cutting blade 4 in the -X direction (see FIG. 1).

[0024] The sizes of the meshes 10, 20, and 30 that subdivide the cutting edges of the workpiece 1, the lower die 2, and the cutting blade 4 are 0.01 mm, and the others are 0.2 to 0.6 mm.

[0025] The shapes of the lower die 2 and the upper die 3 are designed using CAD (computer-aided design), the shape of the cutting blade 4 is reproduced based on the measured values, and the clearance between the end faces of the lower die 2 and the upper die 3 and the end face of the cutting blade 4 is 0.07 mm (measured value). The gap between the lower die 2 and the upper die 3 is set to the thickness of the workpiece 1.

[0026] The workpiece 1 is made of aluminum (A6T02, the fracture condition is that the principal stress is 290.6 MPa and the equivalent plastic strain is 0.89), and the plate thickness is 1.0 mm. The shape of the workpiece 1 is analyzed using the FEM (Finite Element Method) of the drawing process.

[0027] The lower die 2 and the upper die 3 are made equivalent to rigid bodies by multiplying the longitudinal elastic modulus of the aluminum by 100.

[0028] The lower die 2 is fully constrained (constraining the X and Y translations and the Z rotation), and after the movement of the upper die 3 is completed, the cutting blade 4 is constrained in the X translation and the Z rotation and moves in the Y translation direction (the input speed is 200 mm / s).

[0029] The contact condition defines 2D_AUTOMATIC_SURFACE_TO_SURFACE (the name of the contact condition definition required when calculating the contact determination for a 2D model).

[0030] And, as a preparation process (preparation process) before starting the flowchart shown in FIG. 3, as shown in FIG. 1, the workpiece 1 is sandwiched between the lower die 2 and the upper die 3 and is made to protrude from the end faces of the lower die 2 and the upper die 3. In this state, the cutting edges of the workpiece 1, the lower die 2, and the cutting blade 4 are subdivided into a plurality of meshes 10, 20, 30. Note that the size of each of the meshes 10 to 30 is set to be equal to or smaller than the size of the chips 5 to be reproduced.

[0031] After making such preparations, the flowchart shown in FIG. 3 is started. First, in step S1, the cutting edge of the cutting blade 4 is set to contact within the range of the mesh 10 set on the surface of the workpiece 1 (see FIG. 5), and in this state, the cutting blade 4 is displaced (lowered) (pressing process, pressing process).

[0032] As the displacement of the cutting blade 4 progresses, when the cutting edge of the cutting blade 4 contacts the surface of the workpiece 1, a positive (YES) determination is made in step S2, and the process proceeds to the subsequent step S3.

[0033] Note that as the displacement of the cutting blade 4 further progresses, for example, as shown in FIGS. 4 and 5, the workpiece 1 starts to be cut and the portion protruding from the end face of the upper die 3 starts to bend downward. Also, regarding the cutting by the cutting blade 4, as is well known, the portion of the cutting edge of the cutting blade 4 from the start of cutting to a predetermined depth position is shearing, and the portion from the predetermined depth position to passing through the lower surface of the workpiece 1 is breaking. In this breaking process, a part of the cut portion of the workpiece 1 may protrude while plastically deforming outward, and chips 5 may be generated (see FIGS. 8 and 9).

[0034] In step S3, the principal stress and plastic strain generated in the workpiece 1 are measured during the progress of the cutting of the workpiece 1 (measurement process, measurement process).

[0035] Following this step S3, in step S4, it is determined whether the measurement result in this measurement process is less than the threshold value (first determination step, first determination process).

[0036] If an affirmative (YES) determination is made in this step S4, then in step S5, an analysis image (see FIGS. 4 to 7) that reproduces the process of the workpiece 1 deforming as the cutting blade 4 descends, and an analysis image (see FIGS. 8 and 9) that reproduces the state of chips 5 being generated from the workpiece 1 are acquired (acquisition step, acquisition process).

[0037] On the other hand, if a negative (NO) determination is made in step S4 above, then in step S6, it is determined whether the cutting of the workpiece 1 is completed (second determination step, second determination process). Note that the completion of the cutting can be determined by determining whether the cutting edge of the cutting blade 4 has displaced below the lower surface of the workpiece 1.

[0038] If a negative (NO) determination is made in this step S6, then return to step S1. On the other hand, if an affirmative (YES) determination is made in step S6 above, then in step S7, it is recognized that the cutting of the workpiece 1 is completed, and an analysis image (see FIG. 10) showing the cutting completion state is acquired, and then the CAE analysis is terminated (termination step, termination process).

[0039] As described above, in the embodiment to which the present invention is applied, in the CAE analysis, the sizes of the plurality of meshes 10, 20, 30 set for the workpiece 1, the cutting edge of the lower die 2, and the cutting edge of the upper die 3 are set to be equal to or smaller than the size of the chips 5 to be reproduced, and when performing press cutting, the cutting edge of the upper die 3 is brought into contact with the workpiece 1 within the range of the mesh 10 set for the workpiece 1, that is, other than the end portions.

[0040] Thereby, it is possible to acquire an analysis image that reproduces the state of chips 5 being generated when the workpiece 1 is press cut by the CAE analysis.

[0041] That is, since it is possible to reproduce the state in which the scrap 5 is generated during press cutting by CAE analysis, it is possible to confirm the state in which the generation of the scrap 5 is reduced by appropriately changing various conditions of press cutting in the CAE analysis. As a result, it becomes possible to establish a technique for suppressing the generation of the scrap 5 when actually performing press cutting.

[0042] Note that the present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of the claims and within the scope equivalent to the scope.

[0043] Other embodiments of the present invention are shown in FIGS. 11 to 16. In this embodiment, in the CAE analysis, as shown in FIG. 11, a press cutting device 3D-modeled on the XYZ plane is used. In this press cutting device, the cutting blade 4 of the press cutting device of the above-described embodiment is changed to an upper punching blade 4A and a side punching blade 4B.

[0044] As a preparation step (preparation process) before analysis, as shown in FIG. 11, the workpiece 1 is sandwiched between the lower die 2 and the upper die 3 and is made to protrude from the end faces of the lower die 2 and the upper die 3. In this state, the cutting edges of the workpiece 1, the lower die 2, the upper punching blade 4A, and the side punching blade 4B are subdivided into a plurality of meshes (not shown, see reference numerals 10, 20, and 30 in FIG. 4). Note that the size of each of the meshes 10 to 30 is set to be equal to or smaller than the size of the scrap 5 to be reproduced.

[0045] The workpiece 1 is made of aluminum (A6T02, the fracture condition is that the principal stress is 290.6 MPa and the equivalent plastic strain is 0.89), and the plate thickness is 1.0 mm. The shape of the workpiece 1 is analyzed using FEM (Finite Element Method) of the drawing process.

[0046] The lower die 2 and the upper die 3 are made equivalent to a rigid body by multiplying the longitudinal elastic modulus of the aluminum, which is the material of the workpiece 1, by 100 times.

[0047] Regarding the analysis conditions, on the product side (in the Y direction from the cutting edge of the upper punching blade 4A), only the range that affects the analysis results is modeled, and in the X direction, 10 mm is modeled along the shape.

[0048] The size of each mesh for subdividing the cutting edges of the workpiece 1, the lower die 2, the upper punching blade 4A, and the drawing punching blade 4B is 0.0125 mm, and the rest is 0.2 - 0.6 mm.

[0049] For the lower die 2 and the upper die 3, the shape is designed using CAD (computer-aided design). The lower die 2 is fully constrained (constraining translation and rotation in X, Y, and Z). The upper die 3 moves in the Z translation direction so that the gap with the lower die 2 is equal to the thickness of the workpiece 1. The gap between the lower die 2 and the upper die 3 is set to the thickness of the workpiece 1.

[0050] The shape of the upper punching blade 4A is reproduced based on the measured value. After the displacement of the upper die 3 is completed, this upper punching blade 4A is displaced (moved) in the Z translation direction (the input is a speed of 200 mm / s, and translation in X and Y, and rotation in X, Y, and Z are constrained). The clearance between the end face of the upper die 3 and the end faces of the upper punching blade 4A and the drawing punching blade 4B is set to 0.21 mm (measured value).

[0051] The shape of the drawing punching blade 4B is reproduced based on the measured value. After the displacement of the upper punching blade 4A is completed, this drawing punching blade 4B is displaced (moved) in the drawing direction of the drawing punching blade 4B (the input is a speed of 200 mm / s, and translation and rotation other than the drawing direction are constrained).

[0052] The contact condition is defined as ERODING_SURFACE_TO_SURFACE (the name of the contact condition definition effective when performing analysis using 3D solid meshes).

[0053] Next, a method for reproducing the chips 5 by the chip reproduction device through CAE analysis will be described.

[0054] First, as shown in Fig. 12, the workpiece 1 is sandwiched between the lower die 2 and the upper die 3 and is in a state of protruding from the end faces of the lower die 2 and the upper die 3, and the cutting edge of the upper punching blade 4A is brought into contact with the surface of the workpiece 1.

[0055] In this state, as shown in FIGS. 13 to 14, the upward cutting blade 4A is displaced (moved). As the displacement of the upward cutting blade 4A progresses, the workpiece 1 begins to be cut. Regarding this cutting, as is well known, the tip of the upward cutting blade 4A is sheared from the start of cutting to a predetermined depth position, and becomes a fracture from the predetermined depth position until passing through the lower surface of the workpiece 1.

[0056] Then, as shown in FIGS. 15 to 16, by bringing the shaving blade 4B into contact with and displacing (moving) the surface of the protruding portion of the remaining workpiece 1 sandwiched between the lower die 2 and the upper die 3, the protruding portion of the workpiece 1 is cut.

[0057] At the end stage of the cutting, that is, as shown in FIG. 16, when the shaving blade 4B reaches the lower die 2, a part breaks from the cut end of the workpiece 1 and chips 5 are generated.

[0058] Thus, also in this embodiment, similarly to the above embodiment, it is possible to obtain an analysis image that reproduces the state in which chips 5 are generated when the workpiece 1 is press-cut by CAE analysis.

Industrial Applicability

[0059] The present invention is suitably applicable to a chip reproduction device and a chip reproduction method that sandwich a workpiece between a lower die and an upper die, project the workpiece from the end faces of the lower die and the upper die, and lower a cutting blade from above the workpiece to cut with the tip of the upper corner of the end face of the lower die and the tip of the cutting blade, and reproduce the state in which chips are generated.

Explanation of Reference Numerals

[0060] 1 Workpiece 2 Lower die 3 Upper die 4 Cutting blade 5 Chips 10 Mesh of workpiece 1 20 Mesh of lower die 2 30 Mesh of cutting blade 4

Claims

1. A chip reproduction device that sandwiches a workpiece between a lower die and an upper die and projects it from the end faces of the lower die and the upper die, and reproduces the generation of chips when cutting with the cutting edge at the upper corner of the end face of the lower die and the cutting edge of the cutting blade by bringing the cutting blade into contact with the workpiece, comprising: A preparation step of subdividing the workpiece, the cutting edge of the lower die, and the cutting edge of the cutting blade into a plurality of meshes, and setting the size of each mesh to be equal to or smaller than the size of the chips to be reproduced; A pressing step of displacing the cutting blade while bringing the cutting edge of the cutting blade into contact within the range of the mesh on the surface side of the workpiece; A measuring step of measuring the principal stress and plastic strain generated in the workpiece during the process of cutting the workpiece as the cutting blade is displaced; A determination step of determining whether or not the measurement result in the measurement step is less than a threshold value; An acquisition step of acquiring an analysis image reproducing the process of cutting the workpiece as the cutting blade is displaced and an analysis image reproducing the generation of chips from the workpiece when the determination step results in an affirmative determination. A chip reproduction device characterized by executing the above steps.

2. A chip reproduction method that sandwiches a workpiece between a lower die and an upper die and projects it from the end faces of the lower die and the upper die, and reproduces the generation of chips when cutting with the cutting edge at the upper corner of the end face of the lower die and the cutting edge of the cutting blade by bringing the cutting blade into contact with the workpiece, comprising: A preparation process of subdividing the workpiece, the cutting edge of the lower die, and the cutting edge of the cutting blade into a plurality of meshes, and setting the size of each mesh to be equal to or smaller than the size of the chips to be reproduced; A pressing process of displacing the cutting blade while bringing the cutting edge of the cutting blade into contact within the range of the mesh on the surface side of the workpiece; A measuring process of measuring the principal stress and plastic strain generated in the workpiece during the process of cutting the workpiece as the cutting blade is displaced; A determination process of determining whether or not the measurement result in the measurement process is less than a threshold value; An acquisition process of acquiring an analysis image reproducing the process of cutting the workpiece as the cutting blade is displaced and an analysis image reproducing the generation of chips from the workpiece when the determination process results in an affirmative determination. A chip reproduction method characterized by performing the above processes.

Images