Sinbo Precision Valve Core Machining Case Study: Leading Innovation in Fluid Control with Micron-Level Precision

In the world of high-end manufacturing, a difference of a thousandth of a millimeter often determines success or failure.

In the hidden corners of the industrial world, there exists a component small in size yet immense in responsibility—the valve core. As the "heart" of various valves and actuators, the valve core is directly responsible for media shut-off, flow regulation, and direction control. Its performance is paramount to the efficiency and reliability of the entire fluid system.

Sinbo Precision, a leading enterprise in the field of high-end precision manufacturing, recently successfully completed a high-precision valve core processing project, demonstrating its strength in micron-level precision manufacturing technology.

Sinbo Precision's partner for this project is a globally renowned automotive parts supplier specializing in pressure relief valves for automotive engine crankcase ventilation. This valve consists of an injection-molded plastic valve body and a film made of fluororubber.

The customer required an annual production volume of 3 million units, with extremely stringent tolerance requirements—within one hundredth of a millimeter. These components are small and delicate, with a fluororubber film diameter of only 5 mm, which must be precisely inserted into the plastic valve body.

As the valve core requires at least two components to be assembled into a single structure during the multi-way valve assembly process, traditional manufacturing methods suffered from high costs, susceptibility to damage at assembly gaps, and high rejection rates.

Faced with these challenges, Sinbo Precision formed a professional technical team and developed a comprehensive innovative solution.

Precision Material Selection: The valve body was made of hard aluminum LY12, while the valve core used 6061-T6 aluminum bar stock, balancing strength, corrosion resistance, and machinability.

Advanced Processing Equipment: The project utilized vertical machining centers equipped with fixtures such as three-jaw chucks and bench vices to ensure stability and accuracy during processing.

Precision Tooling System: Various precision tools were employed, including 40 insert-type face mills, 100 insert-type face mills, 10 carbide end mills, 16 carbide end mills, and others to meet the needs of different processing stages.

Sinbo Precision's machining process involves several key steps: The process begins with removing excess material from the surface of the raw material. This is followed by allowing active carbon atoms decomposed from the carburizing medium to penetrate the surface layer of the raw material.

Gun drilling is then used for deep hole machining of the workpiece. After this step, the workpiece undergoes further processing to meet product requirements.

Based on milling machine processing, the valve core parts are obtained, including the valve core housing and the connecting rod at the end of the valve core housing. The valve core housing and connecting rod use integral forming technology.

High-frequency induction heating quenching technology is applied to the connection between the valve core housing and the connecting rod. Finally, the workpiece undergoes boring and polishing to ensure the required surface finish and dimensional accuracy.

Sinbo Precision implemented strict quality control measures. The team used various measuring tools for inspection, including micrometers, depth vernier calipers with 0.05mm accuracy, and tape measures.

Through optimization and improvement of the processing technology, the valve cores produced by Sinbo Precision achieved an accuracy of 3 microns, far exceeding the industry average and representing a leading level domestically in China.

For critical areas such as the valve core side and valve body透孔 that require precise fit and high surface finish, Sinbo Precision divided the process into two stages: rough machining and finish machining. During finish machining, the machining allowance and its tolerance were extremely small, with spindle speeds reaching S5000 and feed rates reduced to F200.

Through the implementation of this project, Sinbo Precision achieved significant results:

Improved Production Efficiency: By deploying digital workshops and implementing intelligent transformation, the company gradually improved production efficiency and product quality while reducing frontline operators.

Excellent Quality Indicators: The project achieved a rejection rate at the millionth level, meaning only a very few products out of every million have defects, demonstrating remarkable quality performance.

Significant Cost Benefits: By optimizing processes and reducing waste, Sinbo Precision helped customers reduce operating costs by more than 15% and product defect rates by more than 35%.

Technological Breakthrough