The metal grinding process is a process that relies on cutting and plastic deformation of the material surface to remove the convex portions of the workpiece surface to obtain a smooth surface. It is one of the main methods of precision manufacturing of machine parts. The grinders for grinding the flat or formed surface of the workpiece mainly include horizontal axis rectangular table surface grinders, vertical axis cylindrical table surface grinders, horizontal axis cylindrical table surface grinders, vertical axis rectangular table surface grinders and various special surface grinders.

1. Common types of grinding machine equipment

(1) Horizontal axis rectangular table surface grinder

The workpiece is sucked or clamped by the rectangular electromagnetic operating table and processed Longitudinal reciprocating motion, and transverse intermittent feeding motion along the dovetail guide rail of the slide seat. The slide seat can perform vertical intermittent feed motion along the guide rail of the column, and the workpiece grinding accuracy is high.

(2) Vertical axis cylindrical surface grinder

The vertically mounted spindle grinds the workpiece end-face and can perform intermittent vertical feed motion along the guide rail of the column. The workpiece is mounted on the rotating circular operating area for continuous grinding. In order to facilitate the loading and unloading of workpieces, the circular operating area can also move longitudinally along the bed guide rails.

(3) Horizontal axis cylindrical surface grinder

It is used to grind circular thin workpieces, and can use the operating area to tilt to grind ring-shaped workpieces of varying thicknesses.

(4) Vertical axis rectangular table surface grinder

Because the diameter is larger than the width of the operating area, the grinding area is large, and it is suitable for high-efficiency grinding.

2. Common problems in the grinding process

(1) Grinding process accuracy issues

Grinding accuracy is mainly determined by machine tool accuracy, fixture accuracy and the above-mentioned grinding accuracy. It is formed comprehensively from cutting process parameters. The accuracy and stability of the grinding swing range will affect the straightness of the seating surface busbar, so reasonably determining the grinding accuracy and position of CNC machine tools is also an important parameter to promote the quality of the workpiece.

(2) Grinding process burn problem

Grinding burn will occur when the process parameters are unreasonable or the dimensional accuracy of the blank is not well controlled during the grinding process. This kind of grinding The main factors causing burns include low linear speed, low cutting force, and high stress on the workpiece surface.

(3) Grinding process crack problem

When the selection of grinding parameters is unreasonable, the correction state is not good, single-point grinding occurs, or there is residual stress after heat treatment of the part, After grinding, the grinding surface of the middle hole seat surface will produce cracks or fine cracks. The cracks and fine cracks, especially the cracks at the pressure chamber of the seat surface, will cause cavitation on the edge of the seat surface, which will reduce the fatigue strength of the workpiece. After a period of time, it will Early failure.

(4) Grinding process lubrication issues

Grinding oil mainly plays lubrication, cooling, cleaning and other functions in the process. Sometimes the performance of the grinding oil used does not meet the process. Requirements, at high speeds, it is impossible to penetrate into the surface of deep holes, and oxide films and hardened layers will be produced to make the hardness of the workpiece uneven. This situation often occurs especially in the grinding of the seat surface of the fuel injection nozzle. As a result, the wear resistance, corrosion resistance and fatigue strength of the workpiece are greatly reduced, and the service life of the oil nozzle is shortened.

3. How to select special grinding oil

(1) Extreme pressure performance of grinding oil

Special grinding oil contains sulfide extreme pressure resistance Grinding additives can effectively protect the grinding tools and improve process accuracy.

(2) Chemical properties of grinding oil

Special grinding oil has good chemical stability and will not cause harm to equipment, human body, and environment.

(3) Other properties of grinding oil

Special grinding oil has passed strict tests in terms of viscosity, flash point, pour point, thermal conductivity, etc. to meet the needs of various industries. process requirements.