Gear grinding machine
Provided is a gear grinding machine the maintainability of which can be improved and which is capable of being miniaturized. More specifically, provided is a gear grinding machine wherein a threaded grinding stone ( 17 ) and a workpiece (W) are engaged with each other and are rotated in this state, resulting in the workpiece (W) being ground, and wherein between a dressing position (P 2 ) where the threaded grinding stone ( 17 ) can be dressed and a retreat position (P 1 ) to which a retreat is made from the dressing position (P 2 ) during grinding, a disk dresser ( 66 ) which, by being driven into rotation, dresses the threaded grinding stone ( 17 ) is swung about an axis (C 2 ) which is parallel to an axis (C 1 ) that is the rotational axis for the workpiece (W) and which intersects, at right angles, the direction in which the threaded grinding stone ( 17 ) is fed toward the workpiece (W).
1. A gear grinding machine for use in grinding a gear to be machined while rotating a grinding wheel and the gear in mesh with each other, the gear grinding machine comprising:
a dresser which is rotationally driven to dress the grinding wheel; and
dresser pivoting means for pivoting the dresser between a dressing position where the dresser can dress the grinding wheel and a retreat position where the dresser retreats from the dressing position at the time of grinding, about a pivot parallel to a work rotation axis of the gear and perpendicular to a feed direction of the grinding wheel to the gear, the gear grinding machine characterized in that
the dresser pivoting means comprises:
a rotating portion by which the dresser is rotatably supported and which rotates about the pivot;
a fixing portion by which the rotating portion is rotatably supported;
positioning means for positioning rotation of the rotating portion with respect to the fixing portion;
positioning release means which is provided in the fixing portion and which uses leverage to release the positioning by the positioning means; and
rotation means for allowing the rotating portion to rotate when the positioning release means actuates,
the positioning release means comprises:
a cylinder portion formed in the fixing portion;
a piston member housed in the cylinder portion to be slidable in the direction of the pivot;
an annular groove portion formed in the rotating portion;
a lever having a base end portion swingably supported by the fixing portion and a tip portion held by the piston member;
rollers fitted into the groove portion and rotatably supported by the lever; and
pressure feeding and discharging means for feeding and discharging pressure to/from the cylinder portion to allow the piston member to slide.
2. The gear grinding machine according to claim 1 , wherein
the groove portion is disposed in a through-hole formed in the lever, and
the rollers are rotatably supported on an inner circumferential surface of the through-hole.
3. The gear grinding machine according to claim 1 , wherein
a retainer pin is supported between tip portions of the lever which form a bifurcated shape, and
a retaining groove for holding the retainer pin is formed in the piston member.