Abstract : The lowest manufacturing cost is the ultimate goal of product design. This paper introduces the principles and product design techniques that should be followed in the design process of engineering machinery products, and provides excellent and reasonable products for engineers and technicians, and provides means and methods for reference.
1 product design principles
Reasonable design should make the manufacturing cost the lowest under the premise of ensuring the necessary functions of the product, which is the subject to be explored in this paper.
(l) Customer's requirements for product features and services must be met. The construction machinery provides customers with not only the functions of the products, but also the after-sales services that support these functions. Therefore, in the design process, it is necessary to aim at different functional features of the product, and to make the product have good maintenance convenience.
(2) Comply with the state's industrial development policies and relevant laws and regulations.
(3) Adhere to the principle of “three-oriented†of standardization, generalization and serialization.
(4) Meet the social requirements for environmental protection.
(5) In line with the laws of technological innovation, attach importance to the protection of intellectual property rights.
(6) From the actual process level and production capacity of the enterprise, emphasize the combination of design, process and production. Product design is not just a pattern design, but also a process design and production design. Production design should be studied mainly from the following aspects:
1 simplify the function or shape of the part;
2 to maximize the standardization, generalization and serialization of products;
3 Make the material grades, varieties and specifications specified in the design drawings as consistent as possible with the existing materials;
4 Considering the blank process and the processing process more effectively;
5 Judging the rationality of the process design according to the processing technology, operation rules and related information used in the current normal production of the enterprise;
6Select the dimensional tolerance and surface roughness that can be guaranteed by the mature processing technology;
7 Comprehensive analysis of the information related to the production process, the necessary value engineering analysis of the main components.
2 product design skills
2.1 Adopting the principle of “three linesâ€
(l) Parts should be replaced with standard parts or standard parts or purchased parts.
(2) When designing splines and threads, it should be easy to use standard tools and measuring tools for processing and testing. In particular, priority should be given to the existing tools and measuring tools.
(3) For the design of large structural parts and steel castings, use fasteners that do not need to be tapped as much as possible, such as replacing the screw holes with welded nut plates. When designing large workpieces, consider using a well-formed hole as a reference to weld the nutplate.
(4) Try to use existing mature parts or mature structures and process methods to make the products serialized and generalized. With this "building block" method, the design speed can be accelerated, the prototype period of new product prototypes can be shortened, and the market can be occupied as early as possible.
(5) Establish the company's own “standard parts library†and speed up the design and trial progress. The author's company has now established and gradually improved the “factory standard parts†system and the “factory standard parts libraryâ€, and selected the same or similar parts used in more than three main products as factory standard parts.
(6) Select a uniform taper, consistent thickness and size of the steel casting material as much as possible.
2.2 Improved design from shape and structure
(1) Minimize parts. Combine several parts into one part, for example, change the weldment to a stamped part to reduce the number of parts.
(2) Design the part into a symmetrical structural form.
(3) Designing parts with similar shapes for use in several products to be designed as universal parts.
(4) Simplify the shape of each part, improve the shape of the part, reduce the shape of the bend, and sometimes change the part that is difficult to ensure the dimensional accuracy during the pressing to the welded part.
2.3 Improve the process plan
(l) Avoid unnecessary cutting, especially the cutting of the clamping reference surface.
When welding parts are prepared by welding with a highly automated welding robot, pre-weld processing of the components should be considered to ensure the mutual positional dimensions between the components of the welded parts. Otherwise, the error will be too large and the robot will not be able to automatically track the welding.
(2) Under the premise of ensuring reliable and reasonable use of components, reduce the machining accuracy level requirements such as dimensional tolerance, surface roughness and shape tolerance.
(3) Reduce the bending shape and complexity of parts, reduce scrap rate and manufacturing costs.
Shandong Yiyuantong International Trade Co., Ltd. , https://www.yyttrade.com