JPS6012174B2 - How to check cylindrical workpieces - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for grinding a cylindrical workpiece, and more particularly to a method for preventing deformation of a cylindrical workpiece during chucking in a grinding machine.

In general, grinding of cylindrical thin-walled workpieces such as bearings has been carried out in two stages of rough grinding and finish grinding, or in multiple stages, in order to increase the cycle and improve the finished surface.

In this case, in conventional magnetic chuck grinding, as shown in FIGS. 1A and 1B, the current value of the magnetic coil is kept constant, that is, the chuck force is kept constant, and rough grinding and finish grinding are performed. For this reason, even during finish grinding to finalize the final shape of the workpiece, the chucking force required for rough grinding acts on the workpiece and deforms it, which means that the deformation caused by chucking remains as it is during rough grinding, and after the chuck is released. There was a drawback that the machining accuracy of the workpiece deteriorated. That is, “
If the chuck force is too strong, the workpiece 1 may warp in width on the end face 2 of the workpiece chuck as shown in Fig. 2 A and B.
was fixed on the chuck surface 4 of the packing plate 3 and was ground in a deformed state, and when the chuck was released, the deformation due to the width warp caused the warp to return to its original shape, resulting in poor cylindricity.

In the drawing, 5 is a grinding wheel. 1' is the grinding part of the workpiece 1. Therefore, as shown in Fig. 3A and B, in order to reduce the deformation caused by the chuck force, each grinding wheel is used during grinding and finish grinding. Switching to the chuck force necessary for grinding.In other words, a method of switching the chuck coil current in two stages has been adopted, but in this case as well, the chuck force switching control in this method is effective in reducing the amount of workpiece fleas, etc. It is a complete two-step process performed by detection, and it is difficult to set the chuck force that should be changed, and there is a risk of chucking with an unnecessarily strong force.Furthermore, due to the cutting edge of the grinding wheel, deflection of the grinding wheel spindle, etc. If only two-stage switching is used, the cycle becomes unstable and problems such as slipping occur, and if the amount of finish grinding is small, sufficient workpiece machining accuracy cannot be obtained due to the influence of residual magnetism in the chuck. The invention is
This invention was developed in view of the drawbacks of the above-mentioned substructure, and the structure of the present invention will be explained below according to the embodiment shown in FIGS. 4A, B, and C.

In the drawing, the left half shows the rough grinding area, and the right half shows the finish grinding area.

That is, in the method of the present invention, the grinding power of the grinding wheel during the grinding process is measured as shown in FIG. 4C, and the chucking force, that is, the coil current value, is This system chucks a thin cylindrical workpiece with the minimum chucking force necessary to perform grinding by continuously changing the chucking force. The problem of cycle instability caused by these factors is resolved, deformation due to chuck force is reduced, and the machining accuracy of the workpiece can be improved. A grinding method aimed at preventing deformation during chucking of a thin cylindrical workpiece in a grinding machine, which involves continuously changing the chuck coil current value in response to the grinding power of the grinding wheel during grinding. In this area, there is a method of continuously changing the chuck coil current value in response to the grinding power of the grinding wheel during rough finish grinding, and a method of keeping the chuck coil current value constant during rough grinding to improve the roundness of the workpiece. Two methods are included: a method in which the chuck coil current value is continuously changed in response to the grinding power of the grinding wheel during finish grinding, which has a large influence on the grinding process.

According to the method of the present invention, deformation after grinding (after the chuck force is released) caused by the chuck force when grinding a thin cylindrical workpiece can be completely eliminated. In other words, deformation can be removed to the maximum extent because the workpiece is chucked with an appropriate minimum chuck car that does not cause work slip due to the necessary minimum chuck car grinding force that can withstand the grinding force at the time.

Furthermore, the minimum chuck force mentioned above only needs to be associated with the grinding power, and changes in the diameter of the workpiece, degree of wear of the grinding wheel,
It can be easily set without being affected by the deflection of the grindstone spindle.

[Brief explanation of drawings]

Figures A and B show the relationship between the grinding depth of cut and time and the chuck coil current value and time in the conventional example, respectively, and Figures A and B show the case where the chuck is too strong in the conventional example. Drawings, Figures 8A and 8 are drawings showing a conventional example using second-level switching, and Figures A to C respectively show the relationship between the grinding depth of cut and time and the relationship between chuck coil current value and time according to the present invention. and a diagram showing the relationship between the grinding power of the grinding wheel and time. Figure 21 Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] 1. In grinding a cylindrical workpiece using a magnetic chuck, the chuck coil current value is continuously changed in accordance with the grinding power of the grinding wheel during grinding to reduce the chuck force to the minimum necessary for grinding. A method for checking a cylindrical workpiece, which is characterized by maintaining the workpiece. 2. During rough grinding, the chuck coil current value is kept constant, and during finish grinding, which has a large effect on workpiece machining accuracy, the chuck coil current value is continuously changed in accordance with the grinding power of the grinding wheel to reduce the chuck force to the minimum required for grinding. A method of chucking a cylindrical workpiece according to claim 1, characterized in that: maintaining the cylindrical workpiece.