Screw grinder is a key equipment used in the field of precision machining to manufacture high-precision threads, irregular screws, spiral grooves and other workpieces. Its core lies in the combination of CNC technology and grinding technology to achieve micrometer level machining accuracy. This article will analyze the processing principles, key technologies, and application characteristics.

1、 Basic Processing Principles

　　Screw grinderThe essence of it is to cut the surface of the workpiece through a high-speed rotating grinding wheel, and its core process includes:

1. Workpiece clamping: Fix the screw type workpiece to be processed on the machine tool worktable, and drive the worktable to move longitudinally by a servo motor.

2. Grinding wheel motion: The grinding wheel is driven by a spindle motor to rotate at high speed and form a specific relative motion trajectory with the workpiece.

3. Feed control: The CNC system adjusts the radial cutting depth and axial feed rate of the grinding wheel according to preset parameters, gradually removing material to achieve the design size.

4. Cooling and chip removal: During the machining process, the temperature is reduced by coolant and the grinding chips are washed away to avoid thermal deformation and wheel blockage.

2、 The core technology of thread grinding

1. Precise synchronization of the transmission chain

Thread grinding requires strict matching of the movement between the grinding wheel and the workpiece. The precision transmission chain of the machine tool ensures that for every rotation of the workpiece, the grinding wheel moves accurately along the axial direction by one lead. This process relies on high-precision encoders on the headstock spindle and closed-loop control of the worktable grating ruler to eliminate mechanical errors.

2. Grinding wheel selection and dressing technology

Single line grinding wheel: suitable for precision screw, worm and other workpieces, with a pitch accuracy of 5-6 levels and a surface roughness of Ra0.08 μ m. Its advantage is that the grinding wheel can be easily trimmed and the tooth profile can be flexibly adjusted through a CNC program.

Multi line grinding wheel: divided into longitudinal grinding method and cutting in grinding method. The longitudinal grinding method completes processing by moving the grinding wheel longitudinally, which is suitable for small batch workpieces; The cutting in grinding method has high productivity but slightly lower accuracy, and is commonly used for large-scale tap processing.

3. Automatic tool alignment and intelligent compensation

Modern machine tools are equipped with contact or non-contact tool setting devices, which dynamically correct the wear and clamping errors of the grinding wheel and workpiece by collecting real-time position data of the grinding wheel and workpiece, combined with numerical control algorithms. For example, when the system detects radial wear of the grinding wheel, it will automatically adjust the feed rate to avoid dimensional deviation.

3、 Key influencing factors and quality control

1. Control of grinding force

Grinding force can be decomposed into tangential force, radial force, and axial force. Among them, radial force can easily cause elastic deformation of the workpiece, which needs to be alleviated by optimizing the grain size and hardness of the grinding wheel.

2. Thermal deformation suppression

The high temperature generated during thread grinding may cause workpiece burns or dimensional drift. The solution includes using high-pressure coolant for rapid heat dissipation and using low thermal conductivity grinding wheel bonding agents to reduce heat accumulation.

3. Intelligent function expansion

This machine tool integrates functions such as process parameter optimization and active vibration avoidance. For example, by monitoring the spindle vibration spectrum, the system can automatically adjust the grinding wheel line speed to avoid resonance zones, significantly improving surface quality.

4、 Application Fields and Development Trends

Screw grinders are widely used in the manufacturing of high value-added products such as automotive turbocharger rotors, aerospace precision bolts, and rail transit ball screws. Future technological development will focus on the following directions:

1. Ultra high speed internal thread grinding: Addressing the challenge of internal thread machining, solving the problem of insufficient accuracy caused by space limitations in traditional methods.

2. Integrated composite machining: Integrating turning, grinding, and online measurement functions to achieve "one-time clamping full process machining", shorten the process chain, and improve consistency.

In summary, screw grinders have become precision machining tools in modern manufacturing through the collaborative innovation of precision transmission, intelligent control, and material science. With the upgrading of industrial demand, its technological iteration will continue to push thread machining towards higher efficiency and more complex shapes.