Since the beginning of this year, the Foundry of Yuchai Machinery Co., Ltd. has continuously and thoroughly advanced lean manufacturing, strengthened production management and tightened casting quality, so as to achieve a comprehensive rejection rate of 1.4 percent in the first 11 months, down 25 percent year on year and up to advanced international standards.

To reduce the rejection rate, the Foundry has conducted active exploration and implemented a series of measures to improve casting quality. I Conducting standardized operations, forming certain standards, process specifications and quality documents through the implementation of 16 lean projects and process improvement, perfecting the management system, and building the lean quality management framework; II Conducting regular inspections, and guiding the efficient implementation of lean projects through measures such as lean management platform, weekly (monthly) project evaluation, specialized project inspection, field project inspection, lean knowledge training and lean tool application and popularization; III Applying lean tools, using 5why analysis approach to analyze quality problems, and working out effective prevention and control measures.

In terms of tightening casting quality control and reducing the rejection rate, the Foundry's workshops have summarized some experience. For example, aiming at recurring quality and production problems, Workshop 1 has worked out clear specifications, put technologists in charge by work sections and models to prevent problems and create a favorable atmosphere of internal competition. Workshop 3 has conducted special system control of "sand hole rejects", "sand blast rejects" and "pouring rejects", and implemented quality management process control and quality improvement synchronously, so as to achieve good effects. Workshop 4 has practiced menu-based management during quality control and model control point management, worked out the standards of key post inspection and strengthened field inspections to spot process problems.

Reducing the casting rejection rate is an important way to increase the rate of energy utilization and reduce energy consumption. Guided by the core concept of "Green Development & Harmony Win-win", Yuchai has been exploring and advancing on the way of green casting to continuously inject new vitality into corporate transformation and upgrading.

(Li Shaodong/Yang Mingze)