introduce

With the start of Industry 4.0, a new round of manufacturing revolution is starting around the world, and the advantages of digital manufacturing (DM) have attracted the attention and attention of various manufacturing fields. At present, domestic large-scale equipment manufacturing enterprises are learning from international companies such as Boeing, Airbus and ge, and systematically developing the research and application of digital manufacturing technology. In recent ten years, the aviation manufacturing industry, represented by AVIC, has attached great importance to the research and application of digital technology, vigorously improved the construction of information infrastructure, combined with product development, carried out applied research in three-dimensional digital design, digital simulation and three-dimensional digital technology, and formulated the standards and specifications of enterprise series digital technology, which has become a learning reference example for rail transit equipment manufacturing industry.

1 Current situation of digital manufacturing technology for rail transit vehicles

In recent years, the rail transit vehicle industry has begun to pay attention to three-dimensional digital manufacturing, but the overall level is still relatively backward, mainly in:

1) The digital foundation is weak. The application of information technology in design, technology, manufacturing and other business units has not yet formed an integrated whole; The ability of digital application development is not strong, and the infrastructure is not matched.

2) The design model is limited to the geometric model, which cannot be used as the core of business data, and the three-dimensional model is for reference only; Product manufacturing information, attributes, etc. Limited to two-dimensional expression, design data is published in the form of blueprint.

3) The use of two-dimensional CAPP in the process is limited to editing process documents and publishing process data with paper process cards; Manufacturing adopts ERP and MES system, but it is out of touch with design and technology.

4) The serial mode is adopted in product development, and there are obstacles in information and data exchange between departments, and communication between specialties is not smooth; There are many non-value-added links in the development process, and the production preparation cycle is long and changes frequently.

At the same time, the technology platform of suppliers in the industrial chain is basically in the two-dimensional era, lacking a unified digital technology standard and a basic environment for parallel cooperation among industries.

2. Design and manufacturing technology platform based on single product data source.

The development trend of rail transit vehicles is small batch order production, shorter delivery cycle and numerous personalized demands. How to make full use of the mature vehicle product platform and quickly realize personalized derivative design and manufacturing with high performance, high quality and low cost is a subject that modern rail transit equipment enterprises must face. The design and manufacturing technology platform with single data source involved in this paper is a solution conception and implementation exploration combined with the current technological development trend of industrialization and information integration.

Through the optimized application of design, process and manufacturing information platform, the existing products and technologies of the company are integrated, and the enterprise knowledge base is established to realize the sharing and reuse of product technical data and manufacturing data; Realize modular and personalized rapid customization development; It also provides the necessary data foundation for virtual simulation verification; While improving the product performance, the manufacturability and maintainability of the product are improved.

2. 1 System architecture and platform design

The data management platform designed by CSR Zhuzhou Machinery Co., Ltd. adopts TC system, and the manufacturing process adopts ERP system (including certain MES functions), which has been applied for many years, but the traditional CAPP technology has been out of touch with design and production. After extensive investigation, TCM was selected for process design and management, and the design and process were integrated into the product lifecycle management system (PLM). Secondly, combing the ERP/MES system that has been used for many years, integrating PLM platform and ERP/MES system seamlessly and efficiently, building a single data source design and manufacturing technology platform and designing the overall technical architecture; And realize the digital manufacturing business process from design model and design data to process documents, process models and processing programs, and then to production and maintenance.

The main business models are designed as follows:

Design: gradually explore the top-down design mode, establish a standardized three-dimensional design environment and various product design templates in NX/TC environment, model and modify the design flexibly, quickly and efficiently, and improve the design efficiency. At the same time, the existing manufacturing information expression mode of three-dimensional geometric model plus two-dimensional drawings is changed, and the product geometric information and product manufacturing information are all integrated on the three-dimensional model by using NXPMI tools, and the two-dimensional drawings are gradually cancelled. Using NX/TC collaborative design platform, three-dimensional design analysis and simulation verification are carried out in virtual environment, and digital prototype design is carried out to improve design accuracy and efficiency.

Process: introduce TCM module, integrate process and design based on TC system, and manage three-dimensional structured process design, process technology system and process resource data platform. Taking three-dimensional design model, design BOM and design document as input, three-dimensional process design and process simulation are carried out, and three-dimensional process design document and process BOM are output according to the process technology standard system. Using NX integrated by TC system, 3D tooling design and cam NC machining simulation are carried out. At the same time, actively explore the integration of TC system with welding, assembly, sheet metal, bending and other simulation software, build a process simulation verification and design platform, and form a feedback closed loop.

Manufacturing: ERP/MES system is adopted, and the data link of design BOM, process BOM and manufacturing BOM is opened through the integration of intermediate database and TC system. ERP/MES system receives the data of primary process division and raw material splitting, process route, process material quota and process man-hour quota, design/process change, etc. of TC system process design. Then according to the project plan and process data, the production plan and production resource allocation are issued. Manage the material codes of TC, CAPP and ERP systems in a unified way on the material coding platform, and realize the process management of material planning, procurement, production, logistics and cost. Taking project management as the main line, carry out production management such as production planning, job scheduling, material distribution and completion; Secondly, synchronize with EHR's institutions and personnel to realize the management of production workers.

2.2 Data Source Definition and Delivery Design

In the whole life cycle from product scheme design to operation and maintenance, 3D product model is the core of data organization, and all product definition data, process definition data and manufacturing definition data are developed around 3D model, forming a unified and unique product data source. On this basis, the collaborative relationship between design, technology and manufacturing is carried out.

Realize the management of EBOM, PBOM and MBOM of products, establish the relationship between different BOM organization methods, organize the data of different stages in the whole product life cycle from different angles, and maintain the relationship between them.

Data source definition mainly includes:

1), and establish a standardized product design environment and a unified product model definition.

2) Unified definition and application of product and material codes, which are coded by the code management system.

3) Define the BOM mode of digital products and manage EBOM/PBOM/MBOM in a unified way.

4) Unified definition and management of standard parts and common parts.

5) unify the engineering change mode and establish a closed-loop product engineering change management process system.

2.3 Support specification and standard design

According to the characteristics of rail vehicle manufacturing industry, around the digital three-dimensional design, manufacturing, testing, management and informatization, ASMEY 14.4 1-2003 Code for Implementation of Digital Product Definition Data, ISO16792: 2006 General Rules for Digital Product Definition Data of Technical Product Files and GB/T 24734 are cited.

1) Basic general standards and specifications: including terminology standards, graphic symbols and code standards, 3D design software installation and configuration file application specifications;

2) Three-dimensional engineering application specifications: including three-dimensional design specifications, three-dimensional modeling specifications, three-dimensional labeling specifications, simulation specifications and three-dimensional manufacturing specifications;

3) System application and management standards and specifications: including PDM system basic application standards and specifications, PDM system product drawing document management standards and specifications, PDM system 3D process document standards and PDM system BOM management standards.

2.4 Implementation path and step design

According to the principle of overall planning and step-by-step implementation, the platform construction and application will be carried out.

The first stage: platform construction. At this stage, the business process model is studied, the integrated platform of design, technology and manufacturing is built, and the data link of design, technology, manufacturing and inspection is opened. The key work at this stage is to build a TCM process platform, integrate TC with ERP system, and verify the feasibility of the technology platform through the test and application of the pilot part.

The second stage: platform verification. Based on the verification application of design and manufacturing technology platform, the research of full 3D design and 4BOM data table manufacturing, the whole vehicle project is selected to run on the system platform, and the complete verification technology platform is applied in all business links.

The third stage: optimize the application. At this stage, we will improve and optimize the technical platform, and promote and apply it in many projects within the company, and gradually cover the technical platform to all internal manufacturing processes. In the future, we will consider integrating with subsidiaries in different places.

3 Practice of single product data source design and manufacturing technology platform

In the past three years, around the construction and practical application of single data source design and manufacturing technology platform, a lot of testing and verification work has been carried out, mainly including: software module technology test, software module function test, system integration technology test, system integration function test, parts simulation test and project operation test. In the early stage, the software function module and system integration were tested and verified with the data of seven typical components such as bogie assembly. Then, combined with most of the specific projects, the simulation operation is carried out, and the Macedonia EMU project is selected for online testing.

4 conclusion

Through the above ideas and phased exploration, we can draw the following conclusions:

1) Select TCM for process design and management. Based on TC platform, the process directly reuses the design model. Business adopts integrated project management of design and technology. There is almost no process preparation cycle for the trial production of Macedonia EMU project. Through integration and parallel cooperation, tooling design, machining program preparation and process analysis will be carried out in time. However, during the testing process, it was also found that how to realize top-down design, how to realize collaborative design in different places, how to adapt to early procurement in the case of rapid production, and how to simplify and standardize process design need to be properly solved.

2) Data integration between 2)TC and ERP/MES opens the data link of design, technology and manufacturing. Macedonia EMU project has achieved data homology. However, the following problems still need to be solved: (1) generate the data structure of process BOM based on design BOM, reconstruct BOM from different perspectives, and integrate associated management; Material transfer under the conditions of TCM process planning multi-process route and ERP production scheduling single process route; Data version replacement is transmitted accurately and effectively in multiple systems within the technical platform.

3) Build a design and manufacturing technology platform, which not only solves the problem of single data source, knowledge inheritance and * * *, but also truly reflects the value of digital manufacturing in the design, manufacturing and simulation verification in virtual environment. At present, only part of simulation verification is carried out on individual parts, and each link of verification also exists independently. What needs to be explored and optimized is how to meet the needs of simulation when establishing data model, and how to design, simulate and improve a closed-loop verification feedback system.

4) Using the design and manufacturing technology platform has a great impact on the existing business model of the company's operation and management. In addition to software and hardware facilities, it is also important to follow up the technical standards and management process system suitable for enterprise characteristics in time, even more critical than the system platform itself.

5) Designing and manufacturing technology platforms All kinds of complex software have a certain business scope, and enterprises need to carry out moderate secondary development according to their unique products and operational characteristics. How to make good use of the technology platform without upgrading the software should be considered comprehensively when building the technology platform.

In a word, digital manufacturing technology platform is the basic guarantee to realize digital manufacturing. Through a large number of data tests and trial operation of Macedonia EMU and other projects, CSR Zhuzhou Machinery Co., Ltd. proves that the technical framework and technical route of TC, ERP/MES digital design and manufacturing integrated technology platform can meet the requirements of digital manufacturing technology. The practical application of the Macedonian EMU project has also started our exploration and application of digital manufacturing. However, in order to make the digital manufacturing technology platform serve the company's manufacturing well and make good use of this technology platform, technical aspects still need to focus on: MBD(Model-BasedDefinition) model technology, optimized application of integrated BOM, multi-system integration and digitalization of its management process.

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