Jtekt Corporation

Akira Makiuchi

Hiroshi Morita

Tomoyuki Kasuga

Ikuya Kato

Yoshihiro Somyo

Dai Kiyota

Keita Goto

Kenichi Yabuki

Takafumi Furutate

A master servo motor and a slave servo motor that synchronously drive for rotation a master main spindle provided with a center that supports one end of a work piece and a slave main spindle provided with a center that supports the other end of the work piece are included. Before grinding, a slip detection cycle that detects a limit current value for the servo motors, at which the work piece and the centers slip, is executed and, during grinding, a grinding condition is changed to prevent a slip between the work piece and the centers in advance at the time when any one of current values of the servo motors has reached a slip threshold value set on the basis of the limit current value.

Method and device for preventing slip of work piece

The positions of at least three points, which are circumferentially, and equiangularly, offset from each other, of a peripheral face of a workpiece set on a rotary table are measured using a position detection probe. The amount of runout of the axis of the workpiece and a phase position of the workpiece, at which the runout amount is largest, are calculated from the measured positions of the equiangularly offset points. The rotary table is turned to set the largest runout phase position of the workpiece in a position opposed to a workpiece contact of a centering apparatus. The relative positions of the workpiece and a position detection block are calculated using the position detection probe. The workpiece is centered by moving a centering shaft member of the centering apparatus such that the workpiece contact pushes the workpiece by a distance corresponding to the runout amount.

Workpiece centering apparatus and workpiece centering method

A wheel truing apparatus adapted for use in a cylindrical grinding machine wherein a work head with a work spindle for support of a workpiece and a wheel head with a grinding wheel for grinding the workpiece are mounted on a bed for relative movement in a Z-axis direction parallel with the rotation axis of the work spindle and in an X-axis direction crossing the Z-axis direction, characterized in that the wheel truing apparatus comprises a rotary drive portion mounted on the work head or a member united therewith, and a wheel truing tool supported on the rotary drive portion for rotation therewith, the wheel truing tool being provided at its outer periphery with a truing portion for truing a grinding surface of the wheel brought into contact therewith, wherein the rotary drive portion is placed in a position adjacent to said work head in a tooling area defined by a stroke of the relative movements of said wheel head and said work head in the Z-axis direction and apart from said work spindle radially outward and is arranged in such a manner that the rotation axis line of said truing tool is oriented toward the rotation axis line of said grinding wheel in a condition where said truing portion is retained in contact with the grinding surface of said wheel, whereby the truing portion of said tool is brought into contact with the grinding surface of said wheel by relative movement of said wheel head to said work head for truing the grinding surface.

Truing apparatus of grinding wheel

In a tool spindle device, a tool head is slidably guided along guide members on a support table and is movable by a tool head feed mechanism. A tool spindle with a machining tool such as grinding wheel attached thereto is rotatably supported through antifriction bearings in the tool head. A lubrication mechanism is provided in the tool head for lubricating the antifriction bearings with oil air or oil mist. A space section is formed between the support table and the tool head to house the tool head feed mechanism and the guide members therein. A release passage is provided for releasing the oil air or the oil mist after lubricating the antifriction bearings, into the first space section therethrough to lubricate the tool head feed mechanism and the guide members housed in the space section.

Tool spindle device

In a grinding machine, a bedhas secured thereon a work headwhich rotatably supports a work spindlefor supporting a workpiece W and mounts thereon a slide basereciprocatively movable in a Z-direction parallel to the axis of the work spindle, and a wheel headcarrying a rotating grinding wheelis reciprocatively movable on the slide base in an X-direction intersecting with the Z-direction. A measuring devicefor measuring the dimension of the workpiece ground with the grinding wheel is mounted on an extreme end of a support armsecured to the slide base to extend in the X-direction, through an actuator devicewhich is operable for moving the measuring device between a measuring position for engagement with the workpiece and a parked position for disengagement therefrom. The support arm passes over the workpiece, or passes through a space between the bed and the workpiece, or passes through the inside of the bed.

Growing community of inventors

Anjo, Japan

Akira Makiuchi