In this system, it can be known that the production engineering, die making technology, standardization, trouble shooting, man power, purchase, tool, material, etc。 are connected with a software and hardware, related instructions of wide and deep technology and its theoretical background[1—3]。82235

Fig。 2 shows one of die components drawing by existing Auto-Lisp program under the AutoCAD and Window  environment。

Something of the other die components design have followed to this method and experiences。

2。2。Strip process layout

Fig。 2。 Die component drawing by Auto-Lisp。

The disposition of part on the strip feed unfolding was displayed with a constant area repeatedly。

Due to upper cause, it must be enough that the decision of strip feeding distance (advance, pitch) and disposition of each stage on the strip lay out are performed exactly。 Our intention considered that the best utilization ratio of sheet metal can be obtained as taking the accurate strip process layout design through the theoretical calculation and field experiences [4]。

This is the optimum method of initial die design。 At this time we referred the web size on the strip from database and its related instructions。

Fig。 3。 Flow chart of strip process layout design system。

Fig。 3 shows the flow chart strip process layout design system。 For the design of strip process layout, the first step is how to decide the feeding method according to the quantity of production part, accuracy of production part, material properties, and material thickness, the second step is followed to this flow chart of Fig。 3。 Fig。 4 showing the production part and its developing length (99 mm) used to the thick sheet metal (material: SPCC and thickness: 1。3 mm) production part。 From the strip process layout designing method, we could design the following strip process layout as showing Fig。 5 by Fig。 4 production part drawing。

The strip process layout was considered that the proper sizes are strip width, web-size, advance, notching allowance, etc。 [5,6]。

                                                                                  (b)

Fig。 6。 Result of FEM simulation by DEFORM: (a) operation 1 step 100 meshing, (b) operation 1 step 100 stress line contour, (c) operation 1 step 100 strain line contour, and (d) operation 1 step 100 damaged line contour。

works piercing, and fifth stage performs piloting with a idleness。

The sixth stage is first bending stage, also seventh stage works piercing。

The eighth stage works U-bending as the second bending。We must take care of pilot damage or its fracture through the causes of dislocation on the every stage。 The ninth stage is idle stage。 The l0th stage is sizing stage。 The llth stage works part cutting as a complete stage。 After that, the strip process layout was obtained as a result in Fig。 5。

2。3。Clearance and gap

This experimental press working material is proper thickness as a just in 1。3mm (SPCC)。

Therefore, the clearance is large amount of 0。05mm between punch edge and die edge for the piercing and notch-ing, etc。 At this time the burr at the cutted edge of sheet metal could be created minimized amount in actual production part as a tryout result。

The gap between punch and die wall for the U-bending was taken 1。1 times of material thickness by database and experiences。

Fig。 7。 Die assembling drawing: (a) upper die, (b) front view drawing, and (c) lower die。

2。4。FEM simulation

Fig。 6 shows the result of FEM simulation of U-bending corner by DEFORM programming。