Jig Design Research Articles

Characterization and Application of Hollow-Sphere-Composite Lightweight Materials

The ability to recycle mechanical and structural materials at the end of their useful lifetime is of high importance. The use of non-conventional materials in these applications enables such recycling and provides a number of other advantages, including increased quality, better economics, protection of the environment, and reduction of energy consumption. New lightweight materials, which have similar properties to their more traditional alternatives, are therefore highly significant for some industrial applications. In machine-tool design, for example, it is important to reduce the mass of the moving parts to obtain better dynamic characteristics. The current use of the term ‘lightweight materials’ refers to the lighter metallic materials such as aluminium, titanium, and magnesium. However, in recent years, the application of alternative, recyclable materials has substantially increased, for example the use of polymer concrete for supports, casing, or tables in machine tools with lighter weight and improved thermodynamic properties. An advantage of hollow-sphere-composites (HSC), which mostly consist of hollow spheres with different particle proportions and a reactive resin system, is that they can be recycled with ease. The aim of this article is to evaluate and characterize the mechanical and thermal properties of HSC as necessary input parameters for the design of various machine-tool and robotic system elements. The versatility of HSCs for machine tools and jig design is also demonstrated.

Sound power measurement techniques for powered hand tools

As part of a project to reduce noise induced hearing loss in the construction industry, NIOSH developed a database of sound power level measurements of electric powered hand tools typically used in the construction industry. The tool testing jigs and setups specified and illustrated in ANSI S12.15 were modified to accommodate the higher precision ten‐microphone arrangement used in ISO 3744. ANSI S12.15 is sometimes vague regarding the tool testing jig design, so test jigs were designed to supplement existing specifications in the standard. In the course of the project, test jigs were designed, techniques were devised to improve repeatability of measurements, to reduce waste materials, to reduce measurement setup time, and to reduce data acquisition time. Several types of tools were tested including circular saws, grinders, screw drivers, drills, jig saws, reciprocating saws, miter saws, hammer drills, belt sanders, and impact wrenches. The test jig designs and measurement techniques may help others to save time, reduce waste material, and improve measurement repeatability. Additionally, a microphone was placed in the nominal hearing zone of the tool operator to acquire a time series to assess other sound metrics.

Redeveloping Design Education in Hong Kong?

The Making of the Notions of Design In Chinese-speaking societies, the word “sheji” (design) has a subtle distinction in relation to engineering, manufacturing, and construction projects. In industrial education, it usually has referred to scientific technology, production, and engineering techniques. For instance, early courses at the Hong Kong Technical College included “Structural Design” from the Department of Civil Engineering, “Transistor Radio Design” from the Department of Electrical Engineering, and “Jig and Tool Design,” “Procedure Design,” and even “Workshop Design” from the Department of Production Engineering. These observations indicate how “design” and “design education” in Hong Kong initially aimed at providing technical input in industrial training, intended to develop the local industrial economy in the postwar era. This aim was far removed from any artistic advocacy, even though “art and design” had merged into a distinct category in everyday discourses. Since the 1960s, “visual art” and “design” have tended to be mentioned in the same breath in Hong Kong. Obvious examples include the Education Department’s change in the official subject title from “Art & Craft” into “Art and Design” in 1975. Furthermore, local art education syllabi and textbooks invariably have included “Graphic Design,” “ThreeDimensional Design,” and “Design Principles”; and of most of the design curricular, the like of “Art Appreciation” and “Art History” are indispensable parts. “Art” and “Design” seem to have an inevitably close relationship in Hong Kong—or do they? There was still public debate on whether “design” should be included into the visual arts funding category when the Hong Kong Arts Development Council was established in 1995. Although the problem of defining the difference between design/art/craft/technology has been the subject of more than a century of debate among industrial powers in the West, the idea of an allegiance between Art and Design has only been invented or adopted in the last thirty to forty years in Hong Kong. Is there then a necessary link between visual art and design? Why do we discuss the two ideas together so frequently? In this paper, I will focus on the genesis and development of the current “mainstream” design education in Hong Kong (from the 1 Hong Kong Technical College, Hong Kong Technical College Annual Report 1959/1960. 2 For the public debates, see the following press articles: Leong, Koon Lai, (1995). “Sheji Guiru Shiyi Fen Yibeigeng, Hang Nei jiang Ban Luntan Pieqing Guanxi” (Design Sharing with Visual Art: A Symposium in the Profession to Clarify the Relation-ship). Xianggang Lianhe Bao, September 19, 1995; Fongi (1995). “Yizhanju Xuanju Timing Jiezhi zai Ji, Zhiyi/ Sheji Yunniang Fenjia” (Election Nominations of the Art Development Council will be Closing, Visual Art/ Design are Preparing Their Separation). Xianggang Jingji Ribao, September 20, 1995; Lee, Kam Ping (1995). “Gongping de Shiyi Fanchou Dingyi” (A Fair Definition on the Realm of Visual Art). Xianggang Lianhe Bao, July 27, 1995; Kan, Tai Keung (1995 a). “Qing Gongping Duidai Yingyong Yishu (Shang)” (Treat Art Applications Fairly (First Part)) Xianggang Lianhe Bao, August 7, 1995; Kan, Tai Leung (1995 b). “Qing Gongping Duidai Yingyong Yishu (Xia)” (Treat Art Applications Fairly (Second Part)) Xianggang Lianhe Bao, August 8, 1995.

1402 加工物の剛性と方位特性を考慮した治具設計

1402 加工物の剛性と方位特性を考慮した治具設計

515 加工物の剛性と方位特性を考慮した治具設計(生産加工)

515 加工物の剛性と方位特性を考慮した治具設計(生産加工)

Accessibility and ergonomic analysis of assembly product and jig designs

In the aircraft industry, the design of floor assembly jigs (FAJs) is an important activity that directly affects productivity. It involves tool frame generation and locator and clamp placement to ensure that the assembly components are held properly with respect to each other to meet the required tolerances. The tool designer also has to analyze the design to ensure that the assembly process does not pose accessibility and ergonomics related problems. The current approach is dependent on the experience of the tool designer and the limited visualization possible on commercial CAD systems. This leads to extensive redesign when accessibility and ergonomic related problems are detected on the physical prototype. In this research, an integrated Virtual Reality-based environment is being developed for the analysis of assembly product and jig designs. CAD models of the assembly product and jig are imported into a Virtual Reality (VR)-based visualization system for accessibility analysis. A motion tracking system is integrated to allow ergonomic posture analysis. The combined VR and motion tracking system allows evaluation of alternate assembly sequences and the jig design. In this paper, the theoretical basis for the analysis environment is presented along with details of the prototype implementation of this system. Relevance to industry Floor assembly jigs are used extensively by the aircraft industry. Improvement of their design process will lead to savings in better design and reduced development time and cost. Better designs will require fewer changes after the jigs have been fabricated. The overall result will be a reduction in product realization time and cost and improved product quality.

Machine understanding of manufacturing features

Automated engineering analysis (AEA) of the solid model of a product is an essential task for the implementation of concurrent engineering. AEA has the potential to analyse several design and manufacturing activities in order to reduce the product development time and the associated costs. This especially has been the goal of many American manufacturing companies facing stiff global competition. AEA involves the use of the CAD data base of the product model for several design and manufacturing activities such as process planning, NC path planning, GT coding, assembly analysis, tolerancing, automated jig and fixture design, FEM analysis, heat transfer analysis, etc. The power of AEA can be fully realized if the output from the CAD data is in a higher-level form, i.e., features. However, CAD systems typically store the product information in a lower-level form such as points, edges, faces, etc. This paper presents a rule/graph-based approach for generating higher-level product definition in terms of manufac...

An integrated CAD/CAM/CAT system for body assembly jigs

Abstract For manufacturing body assembly jigs, we have developed a system where all the processes, from jig design to accurate jig machining are performed by continuous operation of CAD/CAM/CAT, and a self-adjusting jig maker which measures and machines jigs in assembled condition by a one-chucking method, and is optimised to accurate machining of jigs. This development has led to improvemen in the quality of jigs and in manufacturing efficiency.

Jigs and Fixtures: Design Review Guidelines for the Ergonomics Engineer

Traditionally, the ergonomics engineer has not played an active role in the design of jigs and fixtures used to manually assemble parts. This is problematic, since tool redesigns are often infeasible due to cost and production constraints. Therefore, less effective measures must be used to control ergonomic hazards, since the hazard(s) cannot be engineered out during the design process. References, guidelines and checklists used by many tool designers do not include ergonomic engineering principles and methods. In addition, many ergonomics engineers may not be schooled in the elements of jig and fixture design, which may reduce their effectiveness as part of the tool design team. The purpose of this paper is to provide the ergonomics engineer with an overview of the design process, and proffer guidelines to assist in the review of jig and fixture designs.

Centrifugal jigging of gravity concentrate and tailing at renison limited

Renison Limited has installed the world's first commercial production application of the modell J650 Kelsey centrifugal jig into its gravity concentration circuit. Laboratory, pilot plant and commissioning work are described together with summaries of experimental and production data. The relationship between feed particle size and ragging retention screen aperture size are shown to be critical to metallurgical performance and operational stability. A description is given of development work on jig design, operation and circuit configuration performed over one year. A comparative analysis of jig performance against conventional shaking tables clearly demonstrated the superior jig performance in terms of concentrate grade and recovery.

Automated design of machining fixtures: tolerance and sequential operations

The long lead time for jig and fixture design is a serious bottle-neck in modern manufacturing. Efforts to automate the fixture design process using intelligent CAD systems have not been taken beyond the prototype stage, mainly because of impediments which include the requirement of complex data structures to represent the workpiece and its attributes. Two deficiencies in existing systems for fixture design are addressed; design for a sequence of operations and design with tolerance considerations. Tolerance and process specifications are obtained from the user during an interactive session. A knowledge-based design system, AutoFix II, designs a fixture for the workpiece. The fixture is optimised for a particular datum specification and sequence of operations. It is analysed and presented via the CAD system. AutoFix II is automated to minimise user-induced errors.

高温負荷装置つき走査型電顕と窒化ケイ素中き裂伝ぱのその場観察

A common difficulty associated with high temperature (above 800°C) in-situ observation of matter in a SEM is the emissions of thermal electrons and light from a heating device and the heated specimen itself, obscuring the image and degrading the resolution. This difficulty was overcome by placing a thermal electron barrier that works as a light shield also.By optimizing the design of testing jigs and these heat shields as well as the bias voltage, in-situ observations of propagation and self-healing of cracks in Si3N4 were successfully conducted at temperatures as high as 1200°C. Also, difference of the effects of moisture on static and cyclic fatigue crack propagations at room temperature was presented.

XPLANE, a Generative Computer Aided Process Planning System for Part Manufacturing

This paper reports on the development of XPLANE, a generative computer aided process planning system for part manufacturing. Described is its position and functioning as a part of a more extended computer aided manufacturing system that includes a link to CAD systems, as well as systems for computer aided design and selection of jigs and fixtures, NC part-program generation, tool management and capacity planning. The XPLANE system automatically selects tools, machining operations and their sequence starting from a full part description created by a boundary-representation solid modeller. Apart from the description of the CAM environment the paper focuses on some of the most important specifications of XPLANE, the knowledge driven expert system, i.e. the knowledge representation, the inference engine, the explain facility and the knowledge-base editor.

Computer Aided Design Using a Knowledge Base Approach and its Application to the Design of Jigs and Fixtures

The design of jigs and fixtures is generally on the critical path of a new product and thus speed is essential in both their design and subsequent manufacture. They must also be well and economically designed. This paper describes an interactive C ADC AM based jig and fixture design procedure which has been developed using a knowledge base which could subsequently become part of an expert system. The approach used both increases the speed of design and encourages designers to improve standardization to speed manufacture. The procedure starts with the component which is to be machined and ends by producing a general arrangement and detail drawings of a finished jig. The paper describes the elements of the software package, JIGS, which implements the procedure. JIGS is shown to offer designers considerable flexibility in its use.

People

M J (Mike) Cassidy has been appointed director of operations with Plessey Aerospace Ltd at Titchfield, Hants and becomes a member of that company's board. Mike (49) joined Plessey at Ilford in 1955 after completing his national service. He was employed in the jig and tool design drawing office.

The Modelling of Electroplating Baths and its Application to Jig Design

SUMMARYIn complex electrochemical systems the intimate relationships between reacting species are difficult to ascertain. However, macroscopic measurements are relatively easy and their interpretation may be assisted by computer analysis techniques. The paper establishes the principles involved in modelling an electrolyte and describes the measurement of overpotentials in hexavalent chromium solutions and the analysis of the resulting information.A review of the mathematical methods available for the solution of boundary value problems is given and the application of two numerical techniques is described with respect to the plating of a print roll. An example illustrating the use of computer methods in jig design is then presented and finally the procedure adopted in establishing secondary current distributions is described.

New competition for jig and tool design

New competition for jig and tool design

An application of diffusion bonding in the construction of a miniature pressure vessel

The diffusion bonding technique has been used to meet an exacting specification calling for the flux-free sealing of a shallow, disc-shaped pressure shell (0.022 × 1.020 in. dia) whose components parts were machined as two separate pieces. The joint involved the simultaneous edgewise bonding of many annular bulkheads 0.005 in. wide and, in the same operation, the fabrication of a pressure valve by sandwiching a thin flexible diaphragm between the valve features machined in each half of the vessel. Relative drift of the valve parts and buckling of the thin outer shell (0.005 in.) of the container during bonding were prevented by careful design of the compression jig. Destructive testing of a trial joint and pressure testing (up to 100 atms) of the finished vessel indicate that the strength of the multiple bond is of the order of that of the parent titanium.

A fast and accurate method of measuring two-port parameters up to 200 MHz

Design and performance of a test jig is described, which permits the measurement of any set of four complex transistor Y parameters in less than one minute. It is particularly convenient that continuous readings can be taken during bias, frequency, or temperature variations. The vector voltmeter indicates approximate results directly in amplitude and phase. Accurate results must be calculated from the readings.

The Control and Characteristics of Acid Alloy Gold Used as a Decorative Plate

SummaryBrief comparison has been made between the alkaline cyanide and acid citrate gold plating baths. Operating conditions of a proprietary acid bath and their effect on cathode efficiency have been investigated. The low gold and nickel metal content generally adopted in these baths and the marked effect of slight variation in these metals on the characteristics of the deposit and trouble-free running of the process make regular analytical control important, as this affects economy of process and quality of product. Brief mention has been made of the application of atomic absorption spectrophotometry as a convenient means of analytical control. Plating distribution can be greatly improved by careful consideration of anode configuration and cathode jig design. The most suitable anode material was found to be gold strip, or as an alternative, platinized expanded titanium mesh. In the proprietary acid bath under consideration, carbon or stainless steel anodes were found to be unsuitable.