Development and application of CAD platform for th

Development and application of gauge CAD platform

[Abstract] gauge CAD platform is a secondary development platform constructed on AutoCAD and pro/engineer development platforms to meet the field of geometric measurement. This paper mainly expounds the composition and function of the platform and the effect of using the platform on the development of design gauge

key words: secondary development of CAD design platform parametric design file management

1 preface

with the rapid development of computer technology, CAD technology is no longer a strange concept for enterprises, and many large and small enterprises have established CAD technology systems. However, how to establish a perfect CAD technology system and give full play to the role of CAD technology in practical work has been puzzling most enterprises

measuring gauge is an important factor to ensure the quality of auto parts. Therefore, it is necessary to change the traditional manual design mode and introduce CAD technology into the design of auto measuring gauge in order to meet the needs of the hot recruitment of auto gold we work partners and the renewal of the car market. We urgently need CAD software with a high degree of specialization. In view of this, we have researched and developed a measuring tool CAD platform

2 overview of measuring tool CAD platform development

2.1 what is platform design mode

in a design, implement strict standardized, serialized and standardized design, and form the basic hardware structure and basic software of a certain type of product field into a unified model of products, that is, the basic platform, and optimize and screen the application software related to the basic platform to form the platform library resources of the basic platform. When developing new products, use the basic platform and select the relevant resources in the platform library

measuring tool CAD platform

2.2 design idea of measuring tool CAD platform

with the development of science and technology and the improvement of living standards, customers have higher and higher requirements for product quality and delivery time. Only with the help of modern design means and advanced design methods can these requirements be met. Therefore, the following strategies need to be adopted in the design method:

1) group technology and similarity principle, adopt standardized technology and modular technology, change the traditional product structure, establish a standardized, modular and serialized design system, make full use of existing mature technology and existing parts, quickly respond to market demand, reduce costs, and improve quality

2) adopt the combined design method to realize the repeated combination of original technology and new technology, expand the repeated effect of standardization results, so as to accelerate the product development process and shorten the product development cycle

3) simple CAD technology can no longer meet the needs of market competition. Therefore, by means of value engineering, virtual reality technology, simulation technology and other means, X-oriented design methods are studied, such as cost oriented design, processing oriented design, testing and maintenance oriented design, product life cycle oriented design, etc

4) improve the innovation ability of enterprises, create new principles and methods by using existing resources, and realize new functions

2.3 basic composition of measuring tool CAD platform

1) secondary development software based on two-dimensional design software AutoCAD

2) 3D design software pro/engineer design platform

3) document management system

4) detection and calculation software

3 overview of measuring tool CAD platform

3.1 secondary development software based on two-dimensional design software AutoCAD

according to the design goal, this part includes standard parts library, common structure library, typical inspection fixture library, parametric design of measuring tool, 500 ⑴ 000mm 2 common drawing tool library

all libraries are developed using Visual LISP language and dialog control language (DCL). It contains more than 200 LISP programs, more than 300 DWG block files, more than 200 slide files, and more than 100000 statements. And all of them are hung in the AutoCAD drawing environment in the form of menus, as shown in the following figure

detection system

common tools

3.1.1 standard parts library

this part of the function is to establish several series of hundreds of standard parts, such as aj4 factory standard, common national standard, common machine tool fixture standard Many parametric libraries, including self-developed general-purpose parts and purchased parts, can directly insert standard parts or purchased parts of various models into the design drawings in a modular manner by invoking the parametric library during design, which greatly facilitates the design work, avoids a lot of repeated labor, and accelerates the design speed

3.1.2 common structure library

this part of the function is to realize the parametric design of full size drive for some common structures. At present, more than 100 varieties of six series have been completed: parametric design of smooth taper mandrel, parametric design of involute spline taper mandrel, parametric design of elastic sleeve mandrel, plug gauge of al1, taper plug (ring) gauge of Al3, caliper gauge of Al0, parametric design of height gauge of Al3, etc. For example, the parametric design of smooth taper mandrel is an auxiliary part often used in the inspection fixture for hole centering. As long as you select the smooth taper mandrel through the menu and input parameters according to the pop-up dialog box (see the above figure), the system will calculate and directly draw the smooth taper mandrel

3.1.3 typical inspection fixture library

this library is built according to the classification of inspection fixtures used by typical parts of professional factories. Summing up the wisdom and experience accumulated by engineers and technicians over the years into the knowledge and rule base in the computer, as a design template for future design, this is an extremely valuable wealth for the design of measuring tools. This part collects more than 100 sets of inspection fixtures for more than 20 typical parts from three professional factories

3.1.4 parametric design of measuring tools

this part of the function is to realize the complete parameterization of the measuring tools that can be parameterized and directly generate engineering drawings as a whole; Elastic sleeve mandrel and portable digital caliper are representative works among them

for example, in the parametric design of the mandrel of the elastic sleeve, the corresponding dialog box (see the above figure) pops up by selecting the menu. After entering the parameters, an A1 engineering drawing is automatically generated. It takes half a day for a designer to design the mandrel of the elastic sleeve, and now it is completed in a few minutes, which greatly improves the design efficiency

3.1.5 common drawing tool library

this part of the function is to deal with the marks of two-dimensional engineering drawings, including intelligent annotation of weld symbols, machining symbols, roughness symbols, pneumatic symbols, etc; Automatic generation of parts list and title block; Rapid input of technical requirements and other documents

3.2 3D design software pro/engineer design platform

with the maturing of cad/cam technology, 3D CAD software on microcomputer platform is developing rapidly. Using three-dimensional design can complete such tasks as finite element analysis, mechanism motion simulation, and numerical control machining, so that in the initial design stage of the product, the appearance and performance of the product are well known. Using the method of combining theoretical design and empirical design, CAD is derived from traditional design and higher than traditional design

the 3D CAD software we use in the design and manufacturing of process equipment is pro/e software launched by PTC (Parametric Technology Corporation) - parameter technology company in the United States. It is still in the initial and exploratory stage, but it has developed rapidly. At present, we have successfully developed a design method of inspection fixture based on three-dimensional data model on this platform, and the pipe template is a typical example of using this design method

pipe template is a common and typical structure in the design of inspection tooling. It is used to verify the space size and shape of various types of pipes. Because the spatial three-dimensional angle of the pipe is complex, in the previous design, it is necessary to calculate manually according to the data provided by the drawing, with a large amount of calculation, and then draw the drawing according to the calculation results. The accuracy of the drawing completely depends on the artificial calculation accuracy. And the integrity is poor, the position and relationship of individual parts are not easy to be accurately guaranteed, and problems are easy to occur in processing

with pro/e software, parts can be accurately established according to product drawings. In the design process, all important data are extracted from the product entity without manual calculation. Then according to the specific design principle, the tooling can be designed accurately and efficiently. It eliminates the influence of human factors on the design, and can ensure the direct connection with the processing department in technology

for example, in the figure below, there are 10 inflection points in the pipe on the left, and the direction of the pipe is mostly spatial size. If it is a two-dimensional design that requires manual calculation, it must also consider using two-dimensional engineering drawings to express, and the three-dimensional design makes the above problems easy to solve

3.3 document management system

this software applies computer information technology based on computer database to realize the electronic management of application form, measuring tool number and this document, thus replacing the archive management mode of manual documents. The computer management of technical documents can ensure the safety and reliability of the managed technical data, effectively improve the query efficiency and reduce the time spent by designers on data query. It includes application form management subsystem and numbering book management subsystem

the application form management subsystem has application form login information, application form allocation information, and application form completion information; Application form query information and application form printing function. See the figure below:

number this management subsystem has the input of inspection fixture number and measuring auxiliary tool number. 1. How to evaluate the realization of the development goal of "1025" new material industry? Query and printing functions

3.4 detection and calculation software

a large number of data queries and complex calculation processes need to be carried out in the design of inspection tools. Therefore, we have developed a detection and calculation software with visual basic language, which includes gears, splines, threads, spindles and common calculation parts in the design of measuring tools. Call the corresponding program, input the necessary data, and the computer will automatically calculate and output the required results to provide reasonable parameters for the design of the inspection tool

4 conclusion

the characteristics of the gauge design are very suitable for the application of CAD technology. Practice has proved that using this platform to design the gauge has the following advantages:

1) it plays a great role in improving the design efficiency, optimizing the design scheme, shortening the design cycle, and improving the degree of "three modernizations" - serialization, generalization, and standardization of functional components

2) designers grow rapidly and can quickly master product design and development technology through platform training

3) completely eradicate a large number of low-level repetitive work in product design and development

4) the knowledge integration of the platform reduces the dependence on individual employees of the enterprise. The normal flow of employees will not affect the technical strength of the enterprise

with the development of computer technology, the measuring tool CAD platform will continue to be updated and improved to meet the needs of professional design. (end)