JPS6147666B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a grinding method.

Workpieces with large machining allowances were usually ground using a grinding device shown in FIG. That is, 1 is the workpiece,
Reference numeral 2 denotes a grindstone, which moves in the direction of arrow 5 with respect to the workpiece 1 to grind the workpiece 1. 3 is a rotary dresser which is rotated by a motor 4 and moves in the direction of arrow 6 for dressing. In the conventional grinding method, as shown in FIG. 1, the workpiece 1 is first mounted on a grinding device, and then the grinding wheel 2 rapidly moves forward and contacts the workpiece 1, and then makes a quick cut.
Rough grinding is performed, and then the rotary dresser 3
The grinding wheel 2 is sharpened by
Slowly move the whetstone to make a cut, perform fine grinding, apply spark out, and quickly retreat to grind workpiece 1.
It was undergoing cycle grinding.

However, the above-mentioned conventional grinding method has the disadvantage that power consumption increases when grinding a workpiece having a large machining allowance.

An object of the present invention is to provide a grinding method that eliminates the above-mentioned conventional drawbacks, reduces grinding resistance, and provides a good finished surface.

That is, the present invention improves the speed at which the grindstone is fed to the grinding wheel side of the rotary dresser or the speed at which the rotary dresser is stopped at the most forward position. This method is characterized by dressing at different times.

The present invention will be explained below based on embodiments shown in the drawings. That is, as shown in FIG. 3, the feeding speed of the rotary dresser 3 to the grindstone 2 is increased to give a rough dressing R, and the feeding speed is slowed to give a fine dressing S.

By the way, Fig. 4 shows rough sharpening R and thin sharpening S.
shows the relationship between the depth from the outermost surface of the grinding wheel and the number of working abrasive grains.

That is, when considering the cutting depth H of the grindstone into the workpiece, in the case of a coarse grain R, the number of working abrasive grains is about 1/4 of that in the case of a fine grain.

FIG. 5a shows the shape of the abrasive grains when the roughness is R, and FIG. 5b shows the shape of the abrasive grains when the sharpness S is fine.

By the way, Fig. 6a shows the relationship between the number of working abrasive grains of the grindstone and the grinding resistance, and Fig. 6b shows the relationship between the number of working abrasive grains of the whetstone and the surface roughness of the workpiece. .

By roughening R in this manner, the number of abrasive grains acting can be reduced and the grinding resistance can be reduced.
However, the surface roughness naturally worsens. On the other hand, thin sharpening S
If this is done, the working resistance will increase, but the surface roughness can be improved.

Based on this principle, an embodiment of the present invention will be described with reference to FIG.

Figure 7 shows the cut cycle diagram of the grindstone into the workpiece (Figure 7a) and the rotary dressing when the grindstone is dressed twice during one plunge grinding cycle in which the grindstone is pressed against the workpiece. This figure shows a cutting cycle diagram (Fig. 7b) for the grindstone of 2. Before the grindstone 2 in Fig. 2 cuts into the workpiece 1, the grindstone 2 is roughly sharpened by the rotary dresser 3. . At this time, the workpiece 1 is attached and detached at the same time. Thereafter, the grinding wheel 2 is rapidly advanced until just before it hits the workpiece 1. Thereafter, the grindstone 2 is cut into the workpiece 1 at an appropriate speed for rough grinding. Next, the cutting of the grindstone 2 is stopped and the rotary dresser 3 is
, and finely sharpen the incision grindstone 2.
After that, the grinding wheel 2 is slowly sent to the workpiece 1 side again to perform precision grinding and cut by a predetermined amount, then the cutting of the grinding wheel 2 is stopped and a spark-out is performed for a certain period of time, after which the grinding wheel 2 rapidly retreats and returns to the home position. , one grinding cycle is completed. Thereafter, the workpiece 1 is removed, a new workpiece is installed, and the above cycle is repeated.

Similarly to the above, a workpiece with a very large grinding allowance can be ground by performing sharpening three or four times during one cycle of cutting into the workpiece with a grindstone. However, increasing the number of times of sharpening too much is not a good idea in terms of efficiency and wear and tear on the whetstone.

As explained above, according to the present invention, even if a workpiece has a large machining allowance, power consumption is small in one cycle, and a good surface roughness can be obtained.

[Brief explanation of the drawing]

Figure 1 is a cycle diagram showing the conventional cutting of a grinding wheel into a workpiece, Figure 2 is a schematic diagram showing the positional relationship between the workpiece, grinding wheel, and rotary dresser, and Figure 3 is a diagram of the rotary dresser. A cycle diagram showing cutting into the grindstone, Figure 4 is a diagram showing the relationship between the number of working abrasive grains measured from the outermost peripheral surface of the grindstone toward the inside of the grindstone,
Figures 5a and b are schematic diagrams of the shape of one abrasive grain when rough and finely polished, respectively. Figure 6a is a diagram showing the relationship between the number of working abrasive grains and grinding resistance.
Figure b shows the relationship between the number of active abrasive grains and surface roughness.
FIG. 7a is a cycle diagram showing cutting into a workpiece by a grindstone according to an embodiment of the present invention, and FIG. 7b is a cycle diagram showing cutting into a grindstone by a rotary dresser at that time. 1... Workpiece, 2... Grinding wheel, 3... Rotary dresser, 4... Motor.

Claims (1)

[Claims] 1. A plunge grinding method in which a grindstone cuts into a workpiece and performs rough grinding and spark-out during one cycle, and is characterized by roughly dressing the grindstone before rough grinding and finely dressing the grindstone before fine grinding. Grinding method.