Numerical control apparatus

• US 4,914,364 A
• Filed: 10/22/1987
• Issued: 04/03/1990
• Est. Priority Date: 10/22/1987
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hirai, Hayao
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): BERGMANN, SAUL
• Application Number:
  US07/111,322
• Time in Patent Office: 894 Days
• Field of Search: 318/590, 318/571, 318/39, 318/573, 318/568, 364/171
• US Class Current: 318/590
• CPC Class Codes: G05B 19/182 characterised by the machine tool function, e.g. thread cutting, cam making, tool direction control G05B19/21 - G05B19/40 take precedence
• CPC Class Codes: G05B 2219/43152 Feed in, transfer line, rapid traverse to work, grip speed
• CPC Class Codes: G05B 2219/50109 Soft approach, engage, retract, escape, withdraw path for tool to workpiece

Abstract

Disclosed herein is a numerical control apparatus for controlling drive spindle heads in a rectangular coordinate system of machining apparatuses such as a lathe, a miller, a laser beam machining apparatus, an electric discharge machining apparatus, a robot and the like, to thereby perform positioning control.

Claims

1. A numerical control apparatus which controls servomotors for driving respective control spindle heads to thereby perform positioning control of a tool or the like relative to a work to be processed or the like, said apparatus comprising:

(a) means for determining whether an instruction in a machining program relates to a rapid-traverse circular-arcuate pass mode or not;

(b) a computation means for computing a distance by which each of said servomotors is caused to move per unit time in the rapid-traverse circular-arcuate pass mode, when said determining means proves that said instruction in said machining program relates to the rapid-reaverse circular-arcuate pass mode; and

(c) a servomotor control means for generating a signal for controlling each of said servomotors in accordance with the result of the computation by said computation means to cause said servomotors to perform the relative positioning in said rapid-traverse circular-arcuate pass mode.

3. A numerical control apparatus according to claim 1 or 2, in which said machining program includes a machining program based on ISO/EIA word address format.

4. A numerical control apparatus according to claim 3, in which codes used in said machining program for instructing said rapid-traverse circular-arcuate pass mode include G codes.

5. A numerical control apparatus according to claim 4, in which said computation means includes means for determining whether numerical data in said machining program are inputs of co-ordinates and a radius, co-ordinate and X- and Y-components, or an angle and a radius.

2. A numerical control apparatus which controls servomotors for driving respective control spindle heads to thereby perform positioning control of a tool or the like relative to a work to be processed or the like, said apparatus comprising:

(a) means for establishing both a control position error parameter exclusively used for a rapid-traverse circulate-arcuate pass mode and a delay error parameter;

(b) means for determining whether an instruction in a machining program relates to a rapid-traverse circulate-arcuate pass mode or not;

(c) a computation means for computing, taking said control position error parameter into consideration, a distance by which each of said servomotors is caused to move per unit time in the rapid-traverse circular-arcuate pass mode, when said determining means proves that said instruction in said machining program relates to the rapid-traverse circular-arcuate pass mode;

(d) a servomotor control means for generating signal for controlling each of said servomotors in accordance with the result of the computation by said computation means to cause said servomotors to perform the relative positioning in said rapid-reaverse circular-arcuate pass mode; and

(e) means for determining when said relative positioning is being carried out by said servomotors in said rapid-traverse circular-arcuate pass mode, whether said positioning is performed within a delay error established by said delay error parameter.