JPS6094263A - Grinding method - Google Patents

Abstract

PURPOSE:To improve the grinding accuracy without injuring a workpiece by grinding the workpiece in the position relation between the workpiece and a grindstone so that the inner-diameter circle which a workpiece draws as a rotary table revolvesy is set in close contact with the outer-diameter circle of the revolving grindstone and swinging the rotary table or the grindstone. CONSTITUTION:A number of workpieces 2 are loaded onto a same circumference on a rotary table 1. The center 3a of the revolution shaft of a grindstone 3 is separated by a distance (b) from the center 1a of the revolution shaft of the rotary table 1 so that the inner-diameter circle 5 which a workpiece 2 draws as the rotary table 1 revolves and the outer-diameter circle 6 of the grindstone 3 are set into close contact. Then, the direction of advance of the workpiece 2 during grinding and the direction of revolution of the grindstone 3 are set nearly parallel, and the contact length between the workpiece 2 and the grindstone 3 is increased. Therefore, when the speed of the rotary table 1 is increased for increasing the grinding efficiency, the impact force for the workpiece 2 is reduced. Therefore, the reduction of the grinding accuracy for the workpiece due to the tilt of the shaft 4 of the grindstone is prevented by swinging the table 1 or the grindstone 3 in a constant cycle in the direction connecting the centers 1a and 3a of revolution shafts of the table 1 or the grindstone 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grinding method for grinding a workpiece with high precision.

The grinding method in a normal rotary type (il) grinder is
As shown in FIG. 1, a large number of workpieces 2 are placed on a rotary table 1 rotating in the direction of the arrow, and ground by a rotary grindstone 6 spaced a distance a from the rotation axis 1α of the rotary table 10. In this method, during grinding, the inner diameter circle 5 drawn by the workpiece 2 as the rotary table rotates 10 times intersects the outer diameter circle 6 of the rotary grindstone 6, so that the workpiece 20 rotation direction A and the grindstone 30 rotation direction B corresponds to a right angle. When the rotational speed of the rotary table 10 is increased in order to increase the grinding efficiency, a strong impact force is generated on the workpiece 2, which has the disadvantage that the workpiece 2 is easily damaged.

Further, as shown in FIG. 2, when the angle θ of the rotating shaft 4 of the grindstone 60 changes due to thermal deformation or the like, the workpiece 2 is ground only by the outer peripheral portion of the grindstone 5. For this reason, whetstone 3
The stiffness of 4d concentrates on a part of the workpiece 2, causing cracks, chips, surface roughness, etc. to occur on the workpiece 2, resulting in 7J:.

The present invention grinds a workpiece in a positional relationship between the workpiece and the grindstone such that the inner diameter circle drawn as the workpiece or rotary table rotates is in contact with the outer diameter circle of the rotary grindstone. The present invention attempts to solve the above-mentioned drawbacks of the conventional methods by performing grinding while swinging a rotary table or a rotary grindstone at a constant period in a direction connecting the rotary axis of the grinding wheel.

The present invention will be explained below based on the embodiments shown in FIGS. 3 to 6.

Figure 6 shows the positional relationship between the workpiece on the rotary table and the rotating grindstone. Workpiece 2 with a multiplicity of g'l 1+S] is placed on the same circumference on rotary table 1, and the rotary table rotates 10 times. As a result, the inner circle 5 drawn by the work 2 is placed in a position where it almost touches the outer diameter 6 of the grindstone 3 (
lJl: Stone 60 rotation axis 6α rotary table 10
It is separated by a distance from the rotation axis 1a.

In this way, when the workpiece 2 is milled, the advancing direction of the workpiece 2 and the rotating direction of the grindstone 3 become almost parallel, and the contact length between the workpiece 2 and the grindstone 6 increases, even if the rotation speed of the rotary table 10 is increased. The impact force on the workpiece 2 is reduced.

In addition, due to thermal deformation, the rotation axis 4 of the Ishi stone 5 is shown as 7 in Fig. 4.
Even if the workpiece 2 is tilted as shown in FIG. 6, the workpiece 2 will grind while hitting the entire surface of the grinding wheel 6, so the workpiece 2 will not be cracked, chipped, or deteriorated in surface roughness.

In addition, the rotary table 1 or the rotary grindstone 3 is connected to the rotary table 10u rotation axis 1α and the grindstone 60u rotation axis 3α.
The inclination of the grinding wheel shaft 4 can be adjusted by swinging it at a certain period (1 to 10 times during one rotation of the rotary table) in the direction connecting the A decrease in the grinding accuracy of the workpiece 2 can also be prevented.

In the present invention, the swinging mechanism of the rotary table 1 is shown in FIG. 5, and the swinging mechanism of the rotary grindstone is shown in FIG. In FIG. 5, a nut 8 is attached to a table 7 installed at the bottom of a rotary table 1, and the nut 8 swings in the direction of arrow C by 100 rotations of a screw shaft caused by the operation of a motor 9. Thereby, the rotary table 1 is configured to swing in the direction C of the rotation axis of the grindstone 10 while rotating.

In FIG. 6, the table 11 is fixed to the rotating shaft 4 of the whetstone 50,
The mechanism is such that the grindstone 6 swings in the rotational axis direction C of the rotary table 10 as the screw shaft 130 rotates due to the operation of the motor 12.

According to the grinding method of the present invention, the surface roughness is 01 μmR□a2 in the conventional method shown in FIG.
1μya Rm, Lχ several times, it is possible to completely prevent cracking, chipping, etc. of the workpiece.

As explained above, according to the four inventions, there is a particular problem.

It is possible to improve the finishing accuracy of brittle grinding processes that prevent chipping, and is useful for providing high-precision workpieces without defects.

[Brief explanation of the drawing]

Figure 1 shows the conventional υ cutting method on a rotary type DT grinding machine, and Figure 2 shows the grinding state when the rotary grindstone is tilted by an angle θ due to the hot-love shape, etc. in Figure 1. Figure 6 is a diagram showing the grinding method of the present invention, Figure 4 is a diagram showing the grinding Bυ state when the rotation axis of the rotary grindstone is tilted at an angle σ before thermal deformation in Figure 3, FIGS. 5 and 6 are diagrams showing the rotary chi table and the swinging mechanism of the grindstone. 1: Rotary table, 1a0 rotation axis center, 2: Workpiece, 3: Grinding wheel, 3a: Rotation axis center, 4: Grinding wheel rotation axis, 5: Inner diameter circle of workpiece, 6: For outer diameter of grindstone.

Claims (1)

[Claims] In a grinding method in which a workpiece placed on a rotary table at a certain distance from the rotation axis of the table is ground using a rotating grindstone, the inner diameter circle drawn by the workpiece as the rotary table rotates is approximately Grinding is carried out in a positional relationship between the workpiece and the rotary whetstone such that they are in contact with the outer diameter circle of the whetstone, and the rotary table or the rotary whetstone is rotated at a certain angle in the direction connecting the rotation axis of the rotary table and the rotation axis of the rotary whetstone. A grinding method characterized by grinding while oscillating periodically.