Rod member feeding device, machine tool including the rod member feeding device and control method for the rod member feeding device

Patent metadata

Field	Value
Publication number	US-12048959-B2
Application number	US-202117192406-A
Country	US
Kind code	B2
Filing date	Mar 4, 2021
Priority date	Mar 27, 2020
Publication date	Jul 30, 2024
Grant date	Jul 30, 2024

Abstract

To provide a rod member feeding device that reduces the load on a spindle chuck and a finger chuck when a rod member is positioned, as well as providing a machine tool provided with the rod member feeding device, and a control method for the rod member feeding device. A rod member feeding device includes: a feed rod for supplying a rod member to a spindle; a servomotor for moving the feed rod along the axial direction of the spindle; and a control device (exemplified with a motor control device and a control device) for controlling the driving of the servomotor. The control device calculates a deviation between a command position based on an advance amount of the feed rod and the actual position of the feed rod that has been actually advanced by the driving of the servomotor, and controls the driving of the servomotor based on the magnitude of the deviation.

First claim

The invention claimed is:

1. A rod member feeding device comprising:
a feed rod for supplying a rod member to a spindle;
a servomotor for moving the feed rod along an axial direction of the spindle; and
a control device for controlling driving of the servomotor,
wherein the control device calculates a deviation between a command position based on an advance amount of the feed rod and an actual position of the feed rod that has been actually advanced by the driving of the servomotor, and wherein
the control device controls the driving of the servomotor so as to retract the feed rod based on a magnitude of the deviation in a state where the rod member is held by the spindle chuck wherein the rod member has been advanced until the front end of the rod member contacts a stopper tool that is provided in front of the spindle and positions the rod member.

2. The rod member feeding device according to claim 1 , wherein the servomotor is driven so as to retract the feed rod by a maximum value of the deviation calculated by sequentially comparing the command position obtained by successively adding the advance amount of the feed rod with the actual position of the feed rod that has been advanced.

3. The rod member feeding device according to claim 2 , wherein the control device stops the driving of the servomotor when a torque value of the servomotor reaches a predetermined torque limit value.

4. A machine tool provided with the rod member feeding device according to claim 2 .

5. The rod member feeding device according to claim 1 , wherein the control device stops the driving of the servomotor when a torque value of the servomotor reaches a predetermined torque limit value.

6. A machine tool provided with the rod member feeding device according to claim 5 .

7. A machine tool provided with the rod member feeding device according to claim 1 .

8. A control method for a rod member feeding device including: a feed rod for supplying a rod member to a spindle; a servomotor for moving the feed rod along an axial direction of the spindle; and a control device for controlling driving of the servomotor,
the control method comprising the steps of:
designating a command position based on an advance amount of the feed rod;
driving the servomotor to rotate in a predetermined direction so as to advance the feed rod by the advance amount;
reading an actual position at which the feed rod has been actually advanced by the servomotor;
calculating a deviation between a designated command value and a read actual position; and
controlling the driving of the servomotor so as to retract the feed rod according to a magnitude of the deviation after the rod member is held by the spindle chuck wherein the rod member has been advanced until the front end of the rod member contacts a stopper tool that is provided in front of the spindle and positions the rod member.

Assignees

• Citizen Watch Co Ltd
• Citizen Machinery Co Ltd

Inventors

• Watanabe Kiyohiko
• Shinohara Takanori
• Shimizu Kenji

Classifications

• B21C51/00

  Measuring, gauging, indicating, counting, or marking devices specially adapted for use in the production or manipulation of material in accordance with subclasses B21B - B21F · CPC title

• G05B19/18

  Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of program data in numerical form (G05B19/418 takes precedence) · CPC title

• B21D43/006 Primary

  Feeding elongated articles, such as tubes, bars, or profiles · CPC title

• B21F23/005 Primary

  Feeding discrete lengths of wire or rod · CPC title