Numerically controlled grinding machine for grinding a tapered surface of a workpiece

• US 5,027,562 A
• Filed: 11/28/1988
• Issued: 07/02/1991
• Est. Priority Date: 11/27/1987
• Status: Expired due to Fees

• Current Assignee: Toyoda Koki Kabushiki Kaisha
• Original Assignee: Toyoda Koki Kabushiki Kaisha
• Inventors: Sawaki, Norikazu, Kobayashi, Akiyoshi
• Primary Examiner(s): Schmidt, Frederick R.
• Assistant Examiner(s): Watson, Bruce P.
• Application Number:
  US07/276,541
• Time in Patent Office: 946 Days
• Field of Search: 51/165.7, 51/165.74, 51/165.75, 51/165.76, 51/165.71, 51/289 R
• US Class Current: 451/11
• CPC Class Codes: B24B 47/22 Equipment for exact control of the position of the grinding tool or work at the start of the grinding operation
• CPC Class Codes: B24B 49/02 according to the instantaneous size and required size of the workpiece acted upon, the measuring or gauging being continuous or intermittent B24B49/12 takes precedence
• CPC Class Codes: B24B 5/14 for grinding conical surfaces, e.g. of centres
• CPC Class Codes: G05B 19/184 Generation of cam-like surfaces

Abstract

Disclosed is a numerically controlled grinding machine for grinding a tapered surface of a workpiece. In the grinding machine, a workpiece having a tapered portion and a reference end surface is supported on a traverse table in such a way that the workpiece is rotatable about an axis intersecting the Z-axis at a predetermined angle, which is equal to an angle formed between the tapered surface and the rotational axis of the workpiece. In addition, a measuring device for measuring the position of the reference surface is mounted on the wheel head.

Claims

1. A numerically controlled grinding machine for grinding a tapered surface of a workpiece, which comprises:

a bed;

a table mounted on said bed;

a swivel table mounted on said table for swiveling movement about a substantially vertical axis;

a wheel head mounted on said bed;

a first moving mechanism for changing positional relationship in an X-axis direction between said wheel head and said table;

a second moving mechanism for changing positional relationship in an Z-axis direction between said wheel head and said table;

workpiece supporting means mounted on said swivel table for selectively supporting a master workpiece having a tapered surface and a workpiece having a tapered surface to be ground in order to rotate said master workpiece and workpiece, said swivel table being located at a predetermined machining angle position so that the rotational axis of said workpiece inclines with respect to the Z-axis direction by a predetermined angle which is equal to an angle formed between the tapered surface and the rotational axis of said master workpiece;

means for feeding said wheel head from a predetermined machining original position along the X-axis direction by a predetermined feed amount so as to grind said tapered surface of said workpiece under the state that said swivel table is located at said predetermined machining angle position;

PG,22

a measuring device having a feeler, said measuring device being supported on said wheel head and being selectively engageable with reference end surfaces of said master workpiece and said workpiece for generating a signal when said feeler of said measuring device engages with said reference end surfaces;

first moving means for simultaneously actuating said first and second moving mechanism in order to move said wheel head from a predetermined measuring original position along a path inclined with respect to the Z-axis direction by said predetermined angle and being parallel to the rotational axis of said workpiece, during a time period when said master workpiece is supported on said table and under the state that said swivel table is located at said predetermined machining angle position, until said feeler of said measuring device engages with said reference end surface of said master workpiece;

first detecting means for detecting a first X-axis position of said wheel head when said signal is generated by said measuring device during movement of said wheel head by said first moving means;

second moving means for simultaneously actuating said first and second moving mechanism in order to move said wheel head from a predetermined measuring original position along a path inclined with respect to the Z-axis direction by said predetermined angle and being parallel to the rotational axis of said workpiece, during a time period when said workpiece is supported on said table and under the state that said swivel table is located at said predetermined machining angle position, until said feeler of said measuring device engages with said reference end surface of said workpiece;

second detecting means for detecting a second X-axis position of said wheel head when said signal is generated by said measuring device during movement of said wheel head by said second moving means; and

means for compensating said predetermined feed amount depending on the difference between said first X-axis position of said wheel head detected by said first detecting means and said second X-axis position of said wheel head detected by said second detecting means.

2. A numerically controlled grinding machine as set forth in claim 1, wherein said compensating means comprises:

means for calculating a compensation value by calculating the positional difference between said first X-axis position and said second X-axis position of said wheel head; and

means for compensating said feed amount of said wheel head by adding said compensation value to said feed amount.

3. A numerically controlled grinding machine as set forth in claim 1, wherein:

said measuring means is supported on said wheel head though a hydraulically operated device which includes means for swinging down said measuring device to a measuring position whereat said feeler of said measuring device is engageable with said reference end surfaces and for swinging up said measuring device to a retracted position whereat said feeler of said measuring device is not engageable with said reference end surfaces.

4. A numerically controlled grinding machine for grinding a tapered surface of a workpiece, which comprises:

a bed,

a wheel head mounted on said bed for movement in an X-axis direction;

a table mounted on said bed for movement in a Z-axis direction which intersects perpendicularly with the X-axis direction;

a swivel table mounted on said table for swiveling movement about a substantially vertical axis;

a first servomotor for moving said wheel head in the X-axis direction;

a second servomotor for moving said table in the Z-axis direction;

a first drive circuit for driving said first servomotor in response to command pulses applied thereto;

a second drive circuit for driving said second servomotor in response to command pulses applied thereto;

workpiece supporting means mounted on said swivel table for supporting a workpiece having a tapered surface in order to rotate said workpiece so that the rotational axis of said workpiece inclines with respect to said Z-axis direction by a predetermined angle, which is equal to an angle formed between the tapered surface and the rotational axis of said workpiece;

first pulse distribution means for distributing a predetermined number of command pulses to said first drive circuit so as to feed said wheel head from a predetermined machining original position along the X-axis direction for grinding operation of said tapered surface of said workpiece to a desired size, under the state that said swivel table is located at said predetermined machining angle position;

a measuring device having a feeler, said measuring device being supported on said wheel head and engageable with a reference end surface of said workpiece for generating a signal when said feeler of said measuring device engages with said reference end surface;

second pulse distribution means for simultaneously distributing command pulses to said first and second drive circuits so as to move said wheel head from a predetermined measuring original position along a path inclining with respect to the Z-axis direction and being parallel to the rotational axis of said workpiece, under the state that said swivel table is located at said predetermined machining angle position, until said feeler of said measuring device engages with said reference end surface;

detecting means for detecting an X-axis position of said wheel head when said signal is generated by said measuring device;

calculation means for calculating the difference between the X-axis position of said wheel head detected by said detecting means and a predetermined theoretical X-axis position of said wheel head, said theoretical X-axis position being indicative of an X-axis position of said wheel head at which said signal would be generated from said measuring device during movement by said second pulse distribution means if said reference end surface of said workpiece is located at a predetermined axial reference position; and

compensating means for changing said number of command pulses distributed by said first pulse distribution means depending on the difference calculated by said calculation means.