AUTOMATIC FEED CONTROL SYSTEM FOR A MACHINE

• US 3,573,588 A
• Filed: 11/21/1968
• Issued: 04/06/1971
• Est. Priority Date: 11/28/1967
• Status: Expired due to Term

• Current Assignee: Meyer Jurgen, Rolf Klinge, Werner Geyer
• Original Assignee: Meyer Jurgen, Rolf Klinge, Werner Geyer
• Inventors: Geyer, Werner, Klinge, Rolf, MEYER JURGEN
• Application Number:
  US04/777,832
• Time in Patent Office: 866 Days
• US Class Current: 318/571
• CPC Class Codes: B23Q 11/04 Arrangements preventing overload of tools, e.g. restricting load
• CPC Class Codes: B23Q 15/00 Automatic control or regulation of feed movement, cutting velocity or position of tool or work programme-control G05B19/00, e.g. numerical programme-control G05B19/18
• CPC Class Codes: B23Q 15/12 Adaptive control, i.e. adjusting itself to have a performance which is optimum according to a preassigned criterion
• CPC Class Codes: B24B 47/20 relating to feed movement
• CPC Class Codes: G05B 19/4163 Adaptive control of feed or cutting velocity without NC B23Q15/12
• CPC Class Codes: Y10T 408/08 with means to regulate operation by use of templet, tape, card, or other replaceable information supply
• CPC Class Codes: Y10T 82/2502 with program control

Abstract

A magnitude which depends upon the forming power of a machine having a machine tool adapted to engage a workpiece is determined. The tool is rapidly driven while it is out of engagement with the workpiece. The drive of the tool is slowed when it engages the workpiece and the magnitude depending upon the forming power of the machine exceeds a lower threshold value.

Claims

1. A method of automatic feed control for a machine having a machine tool adapted to engage a workpiece with forming power, said method comprising:

determining a magnitude which depends upon the forming power of the machine;

rapidly driving the tool while it is out of engagement with the workpiece;

slowing the drive of the tool when it engages the workpiece and the magnitude depending upon the forming power of the machine exceeds a lower threshold value; and

further slowing the drive of the tool as long as the magnitude which depends upon the forming power of the machine exceeds an upper threshold value.

2. A method as claimed in claim 1, wherein the workpiece is formed by cutting and the magnitude which depends upon the forming power of the machine is the torque of the workpiece.

3. A method as claimed in claim 1, wherein the workpiece is formed by cutting, and the magnitude which depends upon the forming power of the machine is the force on the tool.

4. Apparatus for automatic feed control of a machine having a machine tool adapted to engage a workpiece with forming power, said apparatus comprising:

workpiece driving means coupled to said workpiece for driving said workpiece;

workpiece driving control means electrically connected to said workpiece driving means for controlling the operation of said workpiece driving means;

tool driving means coupled to said tool for driving said tool, said tool driving means comprising a first driving motor for driving said tool in directions along a first coordinate axis and a second driving motor for driving said tool in directions along a second coordinate axis perpendicular to the first coordinate axis;

tool driving control means electrically connected to said tool driving means for controlling the operation of said tool driving means, said tool driving control means comprising switching means and threshold switching means having an input electrically connected to said forming power means and an output electrically conneCted via said switching means to said first and second driving motors for producing an output voltage in accordance with the magnitude of the input voltage applied to its input; and

forming power means electrically connected to said tool driving control means for providing a magnitude which depends upon the forming power of the machine and controlling said tool driving control means in accordance with the magnitude which depends upon the forming power of the machine.

5. Apparatus as claimed in claim 4, wherein said tool driving control means includes threshold switching means having an input and an output electrically connected to said tool driving means for producing an output voltage in accordance with the magnitude of an input voltage applied to its input, and said forming power means comprises a torque indicator coupled to said workpiece driving means and electrically connected to the input of the threshold switching means of said tool driving control means.

6. Apparatus as claimed in claim 4, wherein said tool driving control means includes threshold switching means having an input and an output electrically connected to said tool driving means for producing an output voltage in accordance with the magnitude of an input voltage applied to its input, and said forming power means comprises piezoelectric crystal means positioned in the path of movement of the tool in abutment with said tool and electrically connected to the input of the threshold switching means of said tool driving control means.

7. Apparatus as claimed in claim 4, wherein the first driving motor of said tool driving means comprises a step motor coupled to said tool and an electrohydraulic motor coupled to and driving said step motor, and said tool driving control means further comprises voltage-frequency transducing means electrically connected between the output of said threshold switching means and said electrohydraulic motor.

8. Apparatus for automatic feed control of a machine having a machine tool adapted to engage a workpiece with forming power, said apparatus comprising:

workpiece driving means coupled to said workpiece for driving said workpiece;

workpiece driving control means electrically connected to said workpiece driving means for controlling the operation of said workpiece driving means;

tool driving means coupled to said tool for driving said tool, said tool driving means comprising a first driving motor for driving said tool in directions along a first coordinate axis and a second driving motor for driving said tool in directions along a second coordinate axis perpendicular to the first coordinate axis, the first driving motor of said tool driving means comprising a step motor coupled to said tool and an electrohydraulic motor coupled to and driving said step motor;

tool driving control means electrically connected to said tool driving means for controlling the operation of said tool driving means, said tool driving control means comprising switching means and threshold switching means having an input electrically connected to said forming power means and an output electrically connected via said switching means to said first and second driving motors for producing an output voltage in accordance with the magnitude of the input voltage applied to its input;

voltage-frequency transducing means electrically connected between the output of said threshold switching means and said electrohydraulic motor;

second threshold switching means having a common input with said threshold switching means and an output electrically connected to the switching means of said tool driving control means, and said switching means includes a gate circuit having inputs and an output connected to a frequency divider, switch means electrically connectable between the voltage-frequency transducing means of said tool driving control means and an input of said gate means, switch means electrically connectable between the output of said second threshold switching meAns and another input of said gate means and switch means electrically connectable between said frequency divider and said electrohydraulic motor whereby said voltage-frequency transducing means is electrically connected to said electrohydraulic motor via said frequency divider under the control of the output voltage of said second threshold switching means; and

forming power means electrically connected to said tool driving control means for providing a magnitude which depends upon the forming power of the machine and controlling said tool driving control means in accordance with the magnitude which depends upon the forming power of the machine.

9. Apparatus as claimed in claim 8, wherein said threshold switching means comprises amplifier means having a positive feedback, a constant input voltage and an output and a relief circuit comprising first and second diodes having cathodes connected in common and providing the output voltage of said threshold switching means, means connecting the anode of the first diode to the output of said amplifier means and means for applying a constant direct voltage to the anode of the second diode.

10. Apparatus for automatic feed control of a machine having a machine tool adapted to engage a workpiece with forming power, said apparatus comprising:

workpiece driving means coupled to said workpiece for driving said workpiece;

workpiece driving control means electrically connected to said workpiece driving means for controlling the operation of said workpiece driving means;

tool driving means coupled to said tool for driving said tool, said tool driving control means including threshold switching means having an input electrically connected to said forming power means and an output electrically connected to said tool driving means for producing an output voltage in accordance with the magnitude of an input voltage applied to its input, said threshold switching means comprising amplifier means having a positive feedback, a constant input voltage and an output and a relief circuit comprising first and second diodes having cathodes connected in common and providing the output voltage of said threshold switching means, means connecting the anode of the first diode to the output of said amplifier means and means for applying a constant direct voltage to the anode of the second diode;

tool driving control means electrically connected to said tool driving means for controlling the operation of said tool driving means; and

forming power means electrically connected to said tool driving control means for providing a magnitude which depends upon the forming power of the machine and controlling said tool driving control means in accordance with the magnitude which depends upon the forming power of the machine.