NON-DISCRETIZED APPROACH TO VISIBILITY ANALYSIS FOR AUTOMATIC MOLD FEATURE RECOGNITION USING STEP PART MODEL

2012 ◽  
Vol 11 (01) ◽  
pp. 1-16 ◽  
Author(s):  
ANKIT SURTI ◽  
N. V. REDDY
Keyword(s):  
Feature Recognition ◽  
Mold Design ◽  
Visibility Analysis ◽  
Input And Output ◽  
Parting Direction ◽  
Part Model

Undercut feature recognition in automatic mold design requires analyzing the visibility/accessibility of the part along a known parting direction, the existing approaches for which are mostly restricted to polyhedral parts or a particular CAD platform or cannot handle partially accessible faces very well. The present work proposes a projection-based methodology to analyze the visibility of a part from a given parting direction without discretizing the part. An approach to further extract undercut features and generate corresponding side-cores is also presented. The implemented system uses STEP AP214/AP203 part files for input and output and has been successfully validated using parts geometrically similar to those used in literature as well as on a number of industrial parts of greater complexity.

POWERTRAIN MACHINING FEATURE IDENTIFICATION

2004 ◽  
Vol 03 (01) ◽  
pp. 103-110 ◽  
Author(s):  
SANGCHUL PARK
Keyword(s):  
Feature Recognition ◽  
Geometric Algorithms ◽  
Machining Process ◽  
Feature Identification ◽  
Machining Features ◽  
Efficient Procedure ◽  
Machining Feature ◽  
Intuitive Idea ◽  
Machining Process Planning ◽  
Part Model

Presented in this paper is a procedure to identify machining features of powertrain components. Machining feature recognition is one of the most important steps for machining process planning. In the case of powertrain components, the first step is to compare a machined model (finished part model) and the corresponding rough part model to identify the volume which should be removed from the rough part model. In regard to the comparison, the most intuitive idea is to use a 3D BOOLEAN operation. Although this approach looks fine, it might not take advantage of the inherent attributes of powertrain component machining. This paper focuses on two important attributes of powertrain machining: (1) a machined model and the corresponding rough part model are very similar and have many identical faces and (2) a rough part model always contains the machined model. Based on these two attributes, we develop an efficient procedure for identifying powertrain machining features. Since the proposed procedure employs well-known 2D geometric algorithms instead of 3D BOOLEAN operations, it is very efficient and robust.

Die-Casting Feature Recognition for Automated Parting Direction and Parting Line Determination

2006 ◽  
Vol 7 (3) ◽  
pp. 236-248 ◽  
Author(s):  
J. Madan ◽  
P. V. M. Rao ◽  
T. K. Kundra
Keyword(s):  
Feature Recognition ◽  
Die Casting ◽  
Present System ◽  
Related Factors ◽  
Cast Part ◽  
Number Of Factors ◽  
Die Cast ◽  
Determination System ◽  
Parting Direction ◽  
Casting Industry

Determining parting direction and parting line for die-cast parts is a nontrivial task that not only depends upon shape and topology of the part, but also on many process related factors. Normally, a die-casting expert decides parting direction and parting line, intuitively taking into account a large number of factors, and this process can be time consuming and cumbersome in many cases. This study addresses automated determination of parting direction and parting line for a die-cast part from part CAD model. The proposed methodology takes STEP file of the part as input for extracting die-casting features, which consists of protrusion or depression regions of the part. These features are classified into those with single, double, or multiple withdrawal directions. Geometric reasoning is used for feature recognition, which includes nested and interacting features. Global visibility instead of local visibility is used for planning withdrawal direction, which makes the decision arrived by present system closer to industrial practice. Parting line is determined based on selected candidate parting direction considering process constraints and priorities. The contribution of this paper is in terms of development of an automated parting direction and parting line determination system, which is more comprehensive and overcomes limitations of the previous work. Results of this system have been validated with those arrived at by experts from the die-casting industry.

Accessibility Driven Spatial Partitioning for Generating Sacrificial Multi-Piece Molds

2002 ◽  
Author(s):  
Jun Huang ◽  
Satyandra K. Gupta
Keyword(s):  
Mold Design ◽  
Cad Model ◽  
Complex Objects ◽  
Spatial Partitioning ◽  
Functional Part ◽  
Drilling Operations ◽  
Geometrically Complex ◽  
Manufacturing Environments ◽  
Part Model ◽  
Design Steps

This paper describes an algorithm based on accessibility-driven partitioning approach to the design of sacrificial multi-piece molds. We construct gross shape of the mold by subtracting the part model from the mold enclosure and analyze its accessibility. The gross mold shape is partitioned using accessibility information. Each partitioning improves accessibility and we produce a set of mold components that are accessible and therefore can be produced using milling and drilling operations. Our approach has the following advantages. First, by using multi-piece molds we can create geometrically complex objects that are impossible to create using traditional two-piece molds. Second, we make use of sacrificial molds. Therefore, using multi-piece sacrificial molds, we can create parts that pose disassembly problems for permanent molds. Third, mold design steps are significantly automated in our methodology. Therefore, we can create the functional part from the CAD model of the part in a matter of hours and so our approach can be used in small batch manufacturing environments.

A Region Based Method to Automated Design of Multi-Piece Molds with Application to Rapid Tooling

2002 ◽  
Vol 2 (2) ◽  
pp. 86-97 ◽  
Author(s):  
Yong Chen ◽  
David W. Rosen
Keyword(s):  
Linear Programming ◽  
Programming Problem ◽  
Linear Programming Problem ◽  
Problem Formulation ◽  
Automated Design ◽  
Rapid Tooling ◽  
Mold Design ◽  
Molded Parts ◽  
Parting Direction ◽  
Injection Molded

Particularly for rapid tooling applications, delivering prototype parts with turn-around times of less than two weeks requires fast, proven mold design methods. We present a region-based approach to automated mold design that is suitable for simple two-piece molds (consisting of core and cavity), as well as molds with many additional moving sections. In our region-based approach, part faces are partitioned into regions, each of which can be formed by a single mold piece. The basic elements of our approach are concave regions (generalized pockets) and convex faces since these elements are central to the identification of regions. This paper focuses on the initial steps of automated mold design, including a problem formulation, methods for identifying the basic elements from part faces, and combining them into regions. By seeking to minimize the number of mold pieces, different partitions of faces into regions are explored until the smallest number of regions is found. During this process, a linear programming problem is adopted for finding a satisfactory parting direction of a region. Algorithms are presented for the region generating and combining process. Our approach is illustrated with several examples of industrial injection molded parts.

Machining Feature Recognition for Cast Then Machined Parts

1999 ◽  
Author(s):  
Yong Se Kim ◽  
Eric Wang
Keyword(s):  
Feature Recognition ◽  
Machining Process ◽  
Recognition Method ◽  
Machining Features ◽  
Surface Machining ◽  
Sufficient Detail ◽  
Machined Parts ◽  
Machining Operations ◽  
Machining Process Planning ◽  
Part Model

Abstract We present a method to recognize machining features for the domain of cast-then-machined parts. Non-interacting volumetric machining features are recognized through a face pattern based recognition approach, and are filtered out of the part model. From the filtered part model and the specification of part surfaces as being cast or machined, we systematically generate the surface machining features and the starting workpiece, which represents the casting output in sufficient detail to support machining process planning. By subtracting the filtered part from its starting workpiece, we obtain the removal volume that is to be realized through machining operations. We apply the feature recognition method using Alternating Sum of Volumes With Partitioning (ASVP) Decomposition to decompose this removal volume into volumetric machining features.

Automatic Undercut Feature Recognition for Side Core Design of Injection Molds

2003 ◽  
Vol 126 (3) ◽  
pp. 519-526 ◽  
Author(s):  
X. G. Ye ◽  
J. Y. H. Fuh ◽  
K. S. Lee
Keyword(s):  
Feature Recognition ◽  
Graph Matching ◽  
Complex Geometry ◽  
Mold Design ◽  
Injection Mold ◽  
Boolean Operation ◽  
Molded Part ◽  
Injection Mold Design ◽  
The Face ◽  
Representation Scheme

For any undercut region of a plastic molded part, a side core has to be designed to form the complex geometry while avoiding the interference between the injection mold and the plastic molded part (molding). Viewing undercuts as features in the context of injection mold design, this paper presents a new method to recognize both isolated and interacting undercut features extracted from a mold cavity or core. With the introduction of the face property and the EAFEG representation scheme, an undercut feature can be precisely defined by an undercut subgraph. Unlike conventional graph-based methods, which recognize features by graph matching, the proposed algorithm recognizes undercut features by searching the cut-sets of subgraphs. After recognizing undercut features, a Boolean operation is used to generate a side core for each undercut. Rules to eliminate the side core intersection are also presented for implementation.

Extraction of Process Parameters from a Sheet Metal Part Model

2014 ◽  
Vol 592-594 ◽  
pp. 888-893
Author(s):  
Pothala Sreenu ◽  
Ravi Kumar Gupta
Keyword(s):  
Sheet Metal ◽  
Process Planning ◽  
Process Parameters ◽  
Feature Recognition ◽  
Research Work ◽  
Computer Integrated Manufacturing ◽  
Actual Process ◽  
Sheet Metal Part ◽  
Metal Part ◽  
Part Model

Process planning in a computer integrated manufacturing (CIM) requires integrated system for design and manufacturing activities. For sheet metal part, feature recognition and feature reasoning of a product model for process planning is an essential component of CIM environment. Research work for feature recognition and reasoning has been addressed in literature, which is limited to the geometric and topological information but actual process parameters requited for manufacturing operation is still an open issue. Our research is for extraction of process parameters from a sheet metal part model which is in STEP Format. These process parameters can be used in sheet metal manufacturing to control the operations. This paper presents extraction of process parameters for a sheet metal feature from a sheet metal part model (STEP Format). This work then formulates the feature processes in terms of extracted process parameters, material properties, sheet metal dimension and feature dimension. The actual operation in real manufacturing environment is identified as extension of the proposed work. The extraction of process parameters for sheet metal operation is demonstrated with case studies.

An Object-Oriented Feature-Based CAD/CAPP/CAM Integration Framework

1991 ◽  
Author(s):  
Ming-Tzong Wang
Keyword(s):  
Process Planning ◽  
Feature Recognition ◽  
Production Control ◽  
Object Oriented ◽  
Secondary Process ◽  
Integration Framework ◽  
Planning Stage ◽  
Primary Level ◽  
Feature Based ◽  
Part Model

Abstract This paper presents an object-oriented feature-based CAD/CAPP/CAM integration framework in a concurrent engineering environment. The framework which is still under development at Yuan-Ze’s automation center is a layered hierarchy based on an object-oriented feature-based part model. The part model serves as a central database for design, process planning, and manufacturing related activities. Feature-based design approach in conjunction with feature recognition approach is incorporated in this integration framework. This dual approach can balance overall computational efficiency and modeling complexity of the interface between design and process planning. There are three levels at the process planning stage : primary level, secondary level and detailing level. The primary level is concerned with the issues of intermediate shape generation. At the secondary process planning level the intermediate specifications of features and workpieces are determined. The detailing level elaborates on the selection of corresponding facilities and parameters for each manufacturing operation. This manufacturing information is used to drive the downstream CAM activities such as NC part programming, production control and scheduling, operation setup and so forth.

Determination of Mold Parting Direction Based on Automatic Molding Feature Recognition

1999 ◽  
Author(s):  
Zhengchao Gu ◽  
Zhenyong Zhou ◽  
Shuming Gao ◽  
Jiaoying Shi
Keyword(s):  
Feature Recognition ◽  
Recognition Algorithm ◽  
Injection Mold ◽  
Automatic Design ◽  
Molded Part ◽  
Molded Parts ◽  
Automatic Feature Recognition ◽  
Parting Direction ◽  
Injection Molded

Abstract Mold parting direction is an important factor to verify the moldability of a molded part. The determination of mold parting direction is the first step to achieve automatic design of an injection mold or a casting die. A method using automatic feature recognition is proposed in this paper to automatically determine parting direction of an injection mold. Parting direction determination of a molded part consists of three steps in our approach. First, all features of a molded part are recognized using a universal hint-based feature recognition algorithm, and all candidate and feasible parting directions of each feature are determined according to the type of the feature. Then, all candidate parting directions of the molded part are automatically generated from all recognized features candidate parting directions. The optimal parting direction is finally chosen based on certain criteria. The case studies on several industrial parts show that the proposed method is effective and efficient in determining the optimal parting direction of injection molded parts.

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