Research on the Main Problems of Technology and Fixture Design in NC Machining

2021 ◽  
Keyword(s):  
Nc Machining ◽  
Fixture Design

Approach to Machining Setup Process Planning of NC Machine Tools Based on Graph Theory

2012 ◽  
Vol 542-543 ◽  
pp. 1190-1195 ◽  
Author(s):  
Guo Zheng Zhang ◽  
Jiang Han ◽  
You Yu Liu
Keyword(s):  
Graph Theory ◽  
Process Planning ◽  
Machine Tools ◽  
Nc Machining ◽  
Numerical Control ◽  
Machining Process ◽  
Fixture Design ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Machining Process Planning

Setup datum of fixture design is an important factor of Numerical Control (NC) machining process planning. Using graph theory of FTG (Feature Tolerance relationship Graph) and DMG (Datum and Machining feature relationship Graph) technology, the feature relationship was proposed to construct a relational table of DMMT (Datum and Machining and Machine Tools) in NC machining setup process. The degree of graph as a discriminant evidence of the machining setup datum was given, so that the machining setup process planning was correctly designed. Combined with the capability of NC machine tools, the unit normal vector of feature facet between the feature datum and machining facet were multiplied to determine the fixture capability, which provide a reasonable proposal of machining setup process for multi-position rotation and multi-piece fixture design. Finally, a case study of machining setup process planning and multi-piece fixture equipment design from corporation was presented to verify the feasibility of the method that was based on the graph theory.

Typical components of the Nc machining

2013 ◽  
Author(s):  
Kun Wei ◽  
Yuhan Zhang ◽  
Weigang Zheng
Keyword(s):  
Nc Machining

An Axiomatic Design View on Part Orientation Schemes

2014 ◽  
Vol 216 ◽  
pp. 310-315
Author(s):  
Felicia Veronica Banciu ◽  
George Drăghici ◽  
Eugen Pămîntaş
Keyword(s):  
Axiomatic Design ◽  
Design Matrix ◽  
Fixture Design ◽  
Design Rules ◽  
Information Axiom ◽  
Part Orientation

the paper proposes an axiomatic design view of orientation schemes used in fixture design, in context of using the axiomatic design rules and guidance to fixture design. In this paper the axiomatic design, matrix and rules are applied to orientation schemes in order to see what kind of designs result (uncoupled, decoupled) and how can be applied the information axiom to choose among the orientation schemes that one (s) that are best suited for the declared purposes-minimum orientation errors.

Quadratic Sensitivity Analysis of Fixtures and Locating Schemes for Rigid Parts

2000 ◽  
Vol 123 (3) ◽  
pp. 462-472 ◽  
Author(s):  
Johan S. Carlson
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Experiments ◽  
Geometric Constraints ◽  
Fixture Design ◽  
Practical Relevance ◽  
Sensitivity Equation ◽  
Relative Gain ◽  
Contact Points ◽  
Scheme Evaluation ◽  
Error Interaction

The main purpose of locating schemes are to position parts. The locating scheme utilizes tooling elements, referred to as locators, to introduce geometric constraints. A rigid part is uniquely positioned when it is brought into contact with the locators. By using kinematic analysis we derive a quadratic sensitivity equation that relates position error in locators with the resulting displacement of the part held by the locating scheme. The sensitivity equation which depends on the locator positions and the workpiece geometry around the contact points can be used for locating scheme evaluation, robust fixture design, tolerancing and diagnosis. The quadratic sensitivity equation derived in this paper is novel by adequate dealing with locator contact at nonprismatic surfaces, nonsmall errors, locator error interaction effects and locator errors in arbitrary directions. Theory for comparing the relative gain in precision by using the quadratic sensitivity equation instead of the linear is developed. The practical relevance of the quadratic sensitivity equation is tested through numerical experiments.

The Design of the NC Teaching Plotter Based on Single Chip Microcomputer

2014 ◽  
Vol 909 ◽  
pp. 342-345
Author(s):  
Xin Juan Shang
Keyword(s):  
Motor Control ◽  
Teaching Practice ◽  
Nc Machining ◽  
Numerical Control ◽  
Stepper Motor ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Nc Program ◽  
Practice Teaching ◽  
Stepper Motor Control

The NC Teaching Plotter is designed for the practice teaching needs of NC machining, In order to improve current existing practice teaching environment of "many student, less equipment". It explains the NC concept with concise way and demonstrates NC thought by the intuitive operation.In this paper, the design of NC teaching plotter makes interpolation motion between pen and table based on NC program in accordance with the requirement made by user, to draw the graphics by moving the magnet control brush painting through the single chip digital control and the two stepper motor control X, Y two axes feed. The NC teaching plotter which demonstrates more clearly and directly the numerical control idea has high practical value for teaching practice.

Interference-Free Multi-Axis NC Machining of Cylindrical Cam Using Enveloping Element

2009 ◽  
Vol 419-420 ◽  
pp. 333-336
Author(s):  
Jeng Nan Lee ◽  
Chih Wen Luo ◽  
Hung Shyong Chen
Keyword(s):  
Cutting Tool ◽  
Nc Machining ◽  
Model Material ◽  
Solid Model ◽  
End Mill ◽  
Generating Method ◽  
Collision Problem ◽  
Five Axis ◽  
Cutting Path ◽  
Cutting Simulations

To obtain the flexibility of choice of cutting tool and to compensate the wear of the cutting tool, this paper presents an interference-free toolpath generating method for multi-axis machining of a cylindrical cam. The notion of the proposed method is that the cutting tool is confined within the meshing element and the motion of the cutting tool follows the meshing element so that collision problem can be avoided. Based on the envelope theory, homogeneous coordinate transformation and differential geometry, the cutter location for multi-axis NC machining using cylindrical-end mill is derived and the cutting path sequences with the minimum lead in and lead out are planned. The cutting simulations with solid model are performed to verify the proposed toolpath generation method. It is also verified through the trial cut with model material on a five-axis machine tool.

Research on S-gear design, manufacturing and measuring based on NC machining center

2020 ◽  
pp. 095440542098134
Author(s):  
Shao-ying Ren ◽  
Yan-zhong Wang ◽  
Yuan Li
Keyword(s):  
Convex Surface ◽  
Coordinate Measuring Machine ◽  
Nc Machining ◽  
Tooth Profile ◽  
Numerical Control ◽  
Machining Center ◽  
Involute Gear ◽  
Measuring Machine ◽  
Gear Contact ◽  
Nc Machining Center

This article presents a method of design, manufacturing, and measuring S-gear. S-gear is a kind of gear whose tooth profile is an S-shaped curve. The sine (cosine) gear, cycloid gear, polynomial gear, and circular arc gear are all S-gears in essence. In the S-gear transmission, the concave surface of one gear and the convex surface of the other gear contact each other. Therefore, the power transmitted by S-gear is much larger than that of the convex-convex-contact involute gear. Some scholars have studied the characteristics of S-gear, but few have explored its manufacturing. In this article, the Numerical Control (NC) machining technology of S-gear is studied in detail for its industrial application. The polynomial curve is used to construct the tooth profile of the S-gear based on the Gear Meshing Theory. The mathematical model of polynomial S-gear is established, by which involute gear can be represented as a special S-gear. The steps of generating NC codes are described. Then, the S-gear sample is processed with an NC machining center. Finally, the sample is measured with a Coordinate Measuring Machine (CMM), and the measurement results show that the accuracy of the S-gear processed by the NC machining center reaches ISO6. This research provides a feasible approach for the design, manufacturing, and measuring of S-gear.

Sign in / Sign up

Export Citation Format

Share Document