GRINDING METHOD AND GRINDING MACHINE

Abstract

A grinding method of a rotating workpiece W having a cylindrical part 20 and a pair of end faces 21 at both sides of the cylindrical part 20 uses a grinding wheel 10 whose grinding stone is narrower than a finishing width S1 between the end faces 21. In a first grinding step, the grinding wheel 10 is relatively moved to the cylindrical part 20 in a direction crossing the rotational axis of the workpiece W and is shuttled along the rotational axis of the workpiece W at least one time between the finishing width S1 of the end faces 21 until the grinding wheel 10 reaches the cylindrical part. And in a second grinding step, the grinding wheel 10 is moved from one of the end faces 21 to the opposite end face 21 on the cylindrical part 20, so as to finish the end faces 21 to a predetermined width S1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects, features and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description of the preferred embodiments when considered in connection with the accompanying drawings, in which:

FIG. 1 is a schematic plan view of a cylindrical grinding machine of a first embodiment related to the invention,

FIG. 2 is an enlarged partial section view of a workpiece and a grinding wheel of FIG. 1,

FIG. 3 is an explanatory drawing of the first embodiment,

FIGS. 4( a) to 4(d) are step-by-step explanatory drawings of FIG. 3,

FIG. 5 is an explanatory drawing of a second embodiment, and

FIGS. 6( a) and 6(b) are explanatory drawings of a conventional art.

Claims

1. A method of grinding a rotating workpiece having a cylindrical part and a pair of end faces at the sides of the cylindrical part, comprising the steps of: providing a grinding wheel whose grinding stone is narrower than a finishing width between the end faces, wherein the rotational axis of the grinding wheel is parallel to a rotational axis of the workpiece and can move relatively to the workpiece;a first grinding step of feeding the grinding wheel relatively to the cylindrical part in a direction crossing the rotational axis of the workpiece while shuttling the grinding wheel along the rotational axis of the workpiece at least one time between the finishing width of the end faces, until the grinding wheel reaches the cylindrical part; anda second grinding step of traversing the grinding wheel from one of the end faces to the opposite end face on the cylindrical part, so as to finish at least the end faces to a predetermined width.

2. The grinding method according to claim 1, wherein the width of the grinding stone is broader than a pre-grinding width between the end faces.

3. The grinding method according to claim 1, wherein the width of the grinding stone is narrower than a pre-grinding width between the end faces.

4. The grinding method according to claim 1, wherein, in the first grinding step, a shuttling width of the grinding wheel along the rotational axis of the workpiece is constant.

5. The grinding method according to claim 1, wherein, in the first grinding step, a shuttling width of the grinding wheel along the rotational axis of the workpiece gradually increases.

6. The grinding method according to claim 1, wherein a pair of R-parts exists between the cylindrical part and the end faces of the workpiece and the grinding stone of the grinding wheel is formed to correspond to the R-parts; andwherein the R-parts are finished in the second grinding step.

7. A grinding machine for grinding a workpiece having a cylindrical part and a pair of end faces at the sides of the cylindrical part, comprising: a grinding stone of a grinding wheel having a predetermined finishing width in a dimension between the end faces;a head stock adapted to support the workpiece rotatably about a rotational axis;a wheel head adapted to support the grinding wheel rotatably about a rotational axis parallel to the rotational axis of the workpiece;drive units adapted to move the head stock and the wheel head relatively parallel to and perpendicular to the rotational axis of the workpiece;a controller adapted to move the grinding wheel to the cylindrical part and shuttle the grinding wheel at least one time between the finishing width of the end faces in a first grinding step, and to move the grinding wheel from one of the end faces to the opposite end face on the cylindrical part in a second grinding step.

8. The grinding machine according to claim 7, wherein the width of the grinding stone is broader than a pre-grinding width between the end faces.

9. The grinding machine according to claim 7, wherein the width of the grinding stone is narrower than a pre-grinding width between the end faces.

10. The grinding machine according to claim 7, wherein a shuttling width of the grinding wheel along the rotational axis of the workpiece is constant in the first grinding step.

11. The grinding machine according to claim 7, wherein a shuttling width of the grinding wheel along the rotational axis of the workpiece gradually increases in the first grinding step.

12. The grinding machine according to claim 7, wherein a pair of R-parts exists between the cylindrical part and the end faces of the workpiece and the grinding stone of the grinding wheel is formed to correspond to the R-parts; andwherein the R-parts are finished in the second grinding step.