The function of firmware is to tighten and connect mechanical parts, and its application is extremely extensive. Its characteristics are a wide variety of specifications, diverse performance and applications, and high standardization and serialization of products. At present, most enterprises have created standard part libraries (including fasteners), but manual assembly methods are still used during assembly.

This traditional assembly method has the following drawbacks: fasteners are stored locally or in designated locations on the server, and users can select them according to their needs during use. For situations where the hierarchy of standard parts libraries is relatively complex, it is necessary to search level by level, making selection difficult; Fasteners are not assembled in groups and need to be assembled one by one, and complete assembly needs to be achieved between every two components. At least two constraint relationships need to be defined, which is cumbersome and inefficient to operate; When modifying or deleting the specifications of already assembled fasteners, it is necessary to operate one by one, which is inefficient and does not conform to design habits; Generally, fasteners are drilled first before being assembled. The specifications of fasteners are not related to the size of screw holes, and cannot be updated synchronously during design changes; The combination and fitting methods of fasteners require consulting relevant standards or mechanical design manuals, which is inconvenient for enterprises to accumulate and transfer knowledge of commonly used fasteners.

This article focuses on the 3D CAD software Pro/E and conducts some research on the rapid automatic assembly technology of fasteners, and provides implementation methods.

This fastener tool is customized and developed for enterprises, and its basic data comes from the enterprise's standard parts library. The main function is to meet the needs of enterprise customers in the fastener design process, to facilitate the search and retrieval of enterprise standard parts, and to support operations such as grouping, batch assembly, modification, and deletion of fasteners, thereby saving time and improving design efficiency. The specific requirements are as follows: the system belongs to secondary development tools and should adopt advanced software architecture to ensure stable, reliable, scalable, and easy to maintain and upgrade system performance; The system should be seamlessly integrated with 3D CAD design software without affecting its use. In addition, if the enterprise's standard parts library is stored in the PDM system, the tool must also be integrated with the PDM system to read fastener information under the specified path; In order to facilitate the management of fasteners, it is necessary to first sort out the enterprise standard parts library and standardize commonly used fastener specifications, fitting methods, combination methods, etc; Provide a visual and integrated program interface that displays different choices in real-time, allowing for intuitive expression of assembly effects; Automatically record the last operation information, making it easier to repeat the operation.

Quick selection refers to quickly selecting the required fasteners from the specified standard parts library. Its basic idea is to use the program to automatically read the information of the standard parts library under the specified path, and filter and query the attribute parameters such as standard number, specifications, performance level, surface treatment, and material code in the graphical interface. The program automatically obtains a matching fastener model based on the selected fastener information.

This guided selection method can not only quickly select the required fasteners, but also effectively manage and control the commonly used fastener specifications in enterprises.

In addition, in order to enhance the automation of attribute parameter selection in the assembly process, this article also studies the automatic matching function of parameters such as bolts, nuts, washers, etc. When the user selects the nominal diameter of a certain bolt, the system automatically filters out the parameters of nuts, washers, etc. that match the nominal diameter of the selected bolt in the standard parts library information table based on the accuracy level of the opening and the matching method, thereby achieving rapid selection and updating of matching fastener groups.

The implementation of group assembly is one of the key technologies for fastener tools. The core idea is to define the matching fasteners as groups in the assembly model.

Generally, according to the different types of main drive components, fastener groups can be divided into three categories: bolts, screws, and nuts, and multiple different combinations can be defined according to the different types of main drive components. For example, some combinations require the installation of spring washers and flat washers at one end, some combinations have spring washers and flat washers in both directions, and some combinations even have thin nuts at the end, etc. The combination method can also be edited as needed, and after editing, it can be added to the list for easy repetitive operations.

For the convenience of designers to view, a graphical preview is used to render selected fasteners based on their selection (unselected fasteners are displayed in reverse), which can intuitively express the assembly effect, as shown in.

In addition, in order to improve the efficiency of assembly, the software has also studied the functions of batch assembly, quick turnaround, and batch deletion.

1) Batch assembly function: In an assembly, it is often necessary to assemble multiple sets of fasteners of the same specification and matching method. The program automatically places fastener groups in batches by searching for identical hole features.

Combination method 10 bolt 0 top flat washer 1 top spring washer 0 bottom spring washer 0 bottom flat washer 0 nut 0 thin nut added to the list fastener combination method mechanical industry standardization and quality step 6S inch W "inch 2>quick turn function: Rotate the selected fastener group as a whole by 180 degrees and exchange the (mating surfaces) at both ends of the fastener group (bolt side and nut side) to achieve a change in the installation direction of the fastener group.

3) Batch deletion function: For unnecessary fastener groups that have already been assembled, a dialog box will automatically pop up when deleting, prompting the user whether to delete the same batch of fastener groups, and highlighting the characteristics of the same batch of fastener groups, as shown in.

Automatic drilling technology is one of the difficulties in implementing fastener tools. The traditional assembly method usually involves pre opening holes before assembling fasteners, and hole features are often established at the part level, making it impossible to update hole features synchronously with fasteners during design changes, requiring manual modification one by one, making the operation very cumbersome.

Firstly, the program obtains the position of the hole through two interactive operations by the user, one is to select the position of the reference point or reference axis, and the other is to select the two ends of the fastener group.

Then, by setting the specifications and accuracy of the holes through the interface (generally including coarse, medium, and fine), the size of the holes is controlled. As shown in the figure, select "hole data", "hole point axis selection, hole diameter, bolt side, nut side automatic hole opening, high vacuum pneumatic baffle valve cylinder and piston rod diameter selection. The method determined by Huang Bojian from Shenyang Ruifeng Technology Co., Ltd. provides a basis for the selection of high vacuum baffle valve cylinder and piston rod diameter.

A vacuum valve is a component in a vacuum system used to adjust the throttle flow rate, cut off or connect pipelines. The high vacuum baffle valve is powered by compressed air and changes the direction of the air path through an electromagnetic directional valve, executing the opening and closing movement of the cylinder driven baffle valve. It is suitable for opening or isolating airflow in vacuum systems ranging from 1.3x14Pa to 1.0x105Pa. Baffle valves have the advantages of simple structure, short opening and closing time, safety and reliability, durability, and automatic control. They are widely used in high-tech fields such as electronics, chemical industry, metallurgy, aviation, aerospace, materials, biomedicine, atomic energy, and space exploration. The design of the cylinder diameter and piston rod diameter of the high precision pneumatic baffle valve is very important. If the cylinder and piston rod diameter design is not reasonable during the opening and closing of the baffle valve, it can lead to problems such as the valve being unable to open and the opening and closing time being long. This article introduces how to estimate the diameter of a cylinder and piston rod under a given pressure, providing a solution to this problem.

The calculation of specific pressure for the sealing surface of the baffle valve cover is based on an example of a high pressure pneumatic baffle valve with a nominal diameter of DN160, as shown in Table 1. Standardization and quality of the mechanical industry. In addition, the fastener group will automatically record the hole feature information that matches it. When the position of the fastener group moves, the program can be updated to automatically modify the hole feature size that matches it.

Reasonable selection of secondary development tools and languages is the key to program portability. The Pro/TOOLKIT provided by PTC for Pro/E is a powerful secondary development tool for Pro/E. It encapsulates many library functions and header files called for Pro/E's underlying resources, and can be debugged using third-party compilation environments (such as C language, VC++language, etc.). Pro/TOOLKIT provides seamless integration with Pro/E for user programs, software, and third-party programs.

Numbers can enable external applications to securely and effectively access Pro/E databases and applications. Through C language programming and seamless integration of application programs with Pro/E, users and third parties can add the required functions in the Pro/E system. Therefore, the fastener tool software was developed using a combination of VC++and Pro/TOOLKIT.

According to the concept of group assembly, using Microsoft Visual C++for programming, a fastener tool that conforms to assembly habits has been developed on the Pro/E platform of the 3D CAD software. It has achieved functions such as rapid selection of fasteners, group assembly, and intelligent punching, and has been applied in fastener design work. Practice has proven that this tool has a significant effect on improving the efficiency of fastener design, facilitating the accumulation and transmission of commonly used fastener knowledge in enterprises.