The draw die process is to force the flat blank into a cavity of the required shape, and at the same time to confine the metal between the drawing surfaces which is forced to change its form from a flat blank to the desired shape。 This process is de- pendent on the thickness of the metal, depth of the draw, and height of the flange to be formed。

Specification of the die for a particular application must be governed by the engineer who has sufficient experience and knowledge about the operation and construction of the various die shapes。 In the designing process of draw dies, the designer examines whether the panel geometry data has defects or not。 If there is a defect, it should be rearranged。 After this process, the designer points out the punch profile and blank curve among the surfaces and curves which consists the geometry of the panel。

The first step is to determine die face, offset line,  design of  wear  plate, block lifter and gauge。 Next important step is to determine the size and layout of die set。 [1] Finally, several components such as balance block, cushion pin, and rib, etc。 are designed。

3 Development of Design Supporting System for Press Die

In developing the design supporting system the following criteria must be satisfied。 First, the design process should be carried out according to the standardized design work flow。 Second, the design variables are determined by the rules of design proc- esses。 Third, the complex geometry can be checked automatically。

For embodiment, the design rule base is programmed using CATGEO, CATMSP in the CATIA version 4。2。1。 [13] The program is developed on IBM RS/6000 with C++ and IUA for GUI。 The design rules and knowledge are collected by the inter- views of design specialists in the press engineering department of H Motor Company。

The configuration of the system is presented in Figure 1。

Hardware: IBM RS6000 Software: CATIA V4。2。1

Database

CORE Modeler:

Control Language (GUI) :

IUA (Interactive User Access)

ge)

Press Die Design Supporting System

Know-how, Standard, Rule, etc。

Press Die Design System Using Rule-base

Input MODEL

Fig。 1。 Schematic configurations of the developed design system for press die

3。1 The Structure of the Design Supporting System for Press Die

The design supporting system for trim die and draw die design consists of the user interface module, the design process module, and the rule-base module。 The user interface module helps users to design the press die easier and faster。 The design process module controls the input data and the data generated at a design stage so that they can be stored or retrieved systematically。 The rule-base module helps represent- ing the know-how of design specialists and design rules of the automotive indus- try。 The structure of the developed system is shown in Figure 2。 [6]

The proposed system enables the design process to be dialogical one and checks the errors in user input to prevent a failed design。 Hence, the system can be used as an error checking tool as well as design tool。

User Interface

Design Output

Design Model

Design / Manufacturing

Information

Existing Database

Standardization Part

Storage of Design Process

Storage of Design Output

Fig。 2。 Schematic diagram of rule-based system for press die design developed in this system