With the rapid development of engine technology and the gradual improvement of environmental protection requirements, engine parts companies are constantly improving their products in the process of digesting and absorbing foreign technology to meet the ever-increasing low fuel consumption requirements and low friction of engines. Performance indicators such as power consumption. The inlaid chrome-plated Piston ring not only has excellent oil-scraping and wear-resisting properties, but also has low production cost (compared to the surface molybdenum Piston Ring). It is currently preferred by many enterprises at home and abroad, especially in the development or improvement of new diesel engine products. A product design (see Figure 1). The company also made some attempts in the design and processing of this aspect, obtained some experience in processing methods, improved the qualification rate of products, effectively reduced production costs, and met the needs of users.
Figure 1 Inlaid chrome structure
This paper introduces an improved scheme of the chrome-plated/composite chrome plating process on the surface of the piston ring. It strives to optimize the process and improve the tooling design to reduce the power without increasing the production cost of the enterprise. Consumption, material consumption, and improve product qualification rate, in order to reduce production costs and enhance the market competitiveness of enterprises. Business status
The company's current chrome-plating production line is high and low level tanks, used for the production of large quantities of ordinary chrome-plated piston rings, while the same industry produces inlaid chrome-plated piston rings generally using shallow grooves or specially designed plating tanks for production and processing, and the equipment input cost is large. Our goal is to produce high-quality products without increasing the investment in equipment, and to use the original production line for production. Development of processing routes
The process route is: inner and outer circle profiling → clamping → sealing → fine car outer circle → car inlay groove → grinding → supplementary sealing → chrome plating → grinding outer circle → demolition ring → inspection appearance → repairing port → honing → inspection appearance → refining Opening → grinding surface → finished product inspection Preliminary determination of processed varieties and tooling
Firstly, 1000 pieces of φ87mm wedge barrel ring ring are used for the process test. The ordinary finishing car outer round bar is used for punching after punching at the flat side. After the car is set in the groove, the chrome plating workshop is chrome-plated, and the two-hearted rod ring is bolted. The flat joint is clamped (see Figure 2). After installation, it is chrome-plated with the current plating tank, and then plated for subsequent processing.
Processing results and analysis
Figure 2 shows the clamping
1. chrome-plated electric disc 2. clamping the heart stick 3. waiting for the chrome ring 4. pressing the bolt 5. pressing plate
After processing to the finished product, the inspection results showed that 468 pieces were qualified, and the pass rate was 46.8%. The main reason was that the outer round grinding was not round, 512 pieces, 20 pieces were other waste products, the unqualified rate of grinding was 51.2%, and the proportion of scrap rate was higher. The processing results are not satisfactory. Analysis of the causes of waste
After the outer circle of the finished car, the outer circle jumps greatly. When the chrome plate is clamped, the upper and lower concentricity is poor when the two core bars are connected, resulting in serious partial ring after chrome plating. The chrome layer after plating is widely scattered, resulting in a high proportion of the outer ring grinding, and the finished product is qualified. The rate is low. improvement measures
1) The flat part of the clamped bar is changed to the thread design, and the chrome-plated core rod is connected by thread to ensure the upper and lower concentricity, avoiding the partial ring when chrome plating, resulting in excessive ring gap.
2) After the car is set in the groove, the outer circle grinding process is carried out to avoid different heights of the left and right groove of the same piece ring, and the chrome dispersion is eliminated.
3) Improved process route: inner and outer circle profiling → clamping → sealing → fine car outer circle → car inlay groove → grinding outer circle → grinding → supplementary sealing → chrome plating → grinding outer circle → tearing ring → inspection appearance → repairing mouth → Honing → inspection appearance → finishing opening → grinding surface → finished product inspection (see Figure 3).
Improve processing tracking test results
Figure 3 Improved rear ring chrome plating
1. chrome-plated electric disc 2. clamped rod 3. chrome-plated ring 4. joint sleeve
The same process was carried out with 1000 pieces of φ87mm wedge barrel surface ring. After the test, the finished product inspection situation was 952 pieces of genuine, 16 pieces of grinding was not round, 32 pieces of other waste products, the pass rate was 95.2%, the genuine rate was obviously improved, and the power consumption and The consumption of chromic anhydride is obviously reduced, and the improvement effect is obvious. Conclusion
The improved processing method has been used to process φ110mm, φ114mm and other products, and the corresponding product qualification rate is above 94%. The improvement effect is obvious and worthy of promotion.
The test processing scheme not only increases the processing equipment of the enterprise, but also achieves the processing purpose by using the existing processing equipment, effectively improving the qualification rate of the product, reducing the production cost, meeting the needs of the user, and becoming the new economy of the company. growth point.