夹具设计英文文献

A review and analysis of current computer-aided fixture design approaches

Iain Boyle, Yiming Rong, David C. Brown

Keywords:

Computer-aided fixture design

Fixture design

Fixture planning

Fixture verification

Setup planning

Unit design

ABSTRACT

A key characteristic of the modern market place is the consumer demand for variety. To respond effectively to this demand, manufacturers need to ensure that their manufacturing practices are sufficiently flexible to allow them to achieve rapid product development. Fixturing, which involves using fixtures to secure work pieces during machining so that they can be transformed into parts that meet required design specifications, is a significant contributing factor towards achieving manufacturing flexibility. To enable flexible fixturing, considerable levels of research effort have been devoted to supporting the process of fixture design through the development of computer-aided fixture design (CAFD) tools and approaches. This paper contains a review of these research efforts. Over seventy-five CAFD tools and approaches are reviewed in terms of the fixture design phases they support and the underlying technology upon which they are based. The primary conclusion of the review is that while significant advances have been made in supporting fixture design, there are primarily two research issues that require further effort. The first of these is that current CAFD research is segmented in nature and there remains a need to provide more cohesive fixture design support. Secondly, a greater focus is required on supporting the detailed design of a fixture’s physical structure.

2010 Elsevier Ltd. All rights reserved. Contents

1. Introduction (2)

2. Fixture design (2)

3. Current CAFD approaches (4)

3.1 Setup planning (4)

3.1.1 Approaches to setup planning (4)

3.2 Fixture planning (4)

3.2.1 Approaches to defining the fixturing requirement (6)

3.2.2 Approaches to non-optimized layout planning (6)

3.2.3 Approaches to layout planning optimization (6)

3.3 Unit design (7)

3.3.1 Approaches to conceptual unit design (7)

3.3.2 Approaches to detailed unit design (7)

3.4 Verification (8)

3.4.1 Approaches to constraining requirements verification (8)

3.4.2 Approaches to tolerance requirements verification (8)

3.4.3 Approaches to collision detection requirements verification (8)

3.4.4 Approaches to usability and affordability requirements verification (9)

3.5 Representation of fixturing information (9)

4. An analysis of CAFD research (9)

4.1 The segmented nature of CAFD research (9)

4.2 Effectively supporting unit design (10)

4.3 Comprehensively formulating the fixturing requirement (10)

4.4 Validating CAFD research outputs (10)

5. Conclusion (10)

References (10)

1. Introduction

A key concern for manufacturing companies is developing the ability to design and produce a variety of high quality products within short timeframes. Quick release of a new product into the market place, ahead of any competitors, is a crucial factor in being able to secure a higher percentage of the market place and increased profit margin. As a result of the consumer desire for variety, batch production of products is now more the norm than mass production, which has resulted in the need for manufacturers to develop flexible manufacturing practices to achieve a rapid turnaround in product development.

A number of factors contribute to an organization’s ability to achieve flexible manufacturing, one of which is the use of fixtures during production in which work pieces go through a number of machining operations to produce individual parts which are subsequently assembled into products. Fixtures are used to rapidly, accurately, and securely position work pieces during machining such that all machined parts fall within the design specifications for that part. This accuracy facilitates the interchangeability of parts that is prevalent in much of modern manufacturing where many different products feature common parts.

The costs associated with fixturing can account for 10–20% of the total cost of a manufacturing system [1]. These costs relate not only to fixture manufacture, assembly, and operation, but also to their design. Hence there are significant benefits to be reaped by reducing the design costs associated with fixturing and two approaches have been adopted in pursuit of this aim. One has concentrated on developing flexible fixturing systems, such as the use of phase-changing materials to hold work pieces in place [2] and the development of commercial modular fixture systems. However, the significant limitation of the flexible fixturing mantra is that it does not address the difficulty of designing fixtures. To combat this problem, a second research approach has been to develop computer-aided fixture design (CAFD) systems that support and simplify the fixture design process and it is this research that is reviewed within this paper.

Section 2 describes the principal phases of and the wide variety of requirements driving the fixture design process. Subsequently in Section 3 an overview of research efforts that have