Numerical control device for tool machine

• US 8,478,439 B2
• Filed: 07/03/2009
• Issued: 07/02/2013
• Est. Priority Date: 08/26/2008
• Status: Expired due to Fees

• Current Assignee: Shin Nippon Koki Co., Ltd.
• Original Assignee: Shin Nippon Koki Co., Ltd.
• Inventors: Nishibashi, Nobutaka
• Primary Examiner(s): Padmanabhan, Kavita
• Assistant Examiner(s): DUNN, DARRIN D
• Application Number:
  US13/060,443
• Publication Number:
  US 20110153057A1
• Time in Patent Office: 1,460 Days
• Field of Search: 700/3, 700/13, 700/19, 700/28, 700/61, 700/69, 700/192, 318/599, 318/603, 318/625
• US Class Current: 700/192
• CPC Class Codes: G05B 19/4103 Digital interpolation
• CPC Class Codes: G05B 19/4141 characterised by a controller or microprocessor per axis
• CPC Class Codes: G05B 2219/34167 Coarse fine, macro microinterpolation, preprocessor
• CPC Class Codes: G05B 2219/50013 Two spindles on same line, one for workpiece, other for tool, second tool on slide
• CPC Class Codes: G05B 2219/50052 Orienting workpiece relative to tool

Abstract

A numerical control device includes a primary distribution pulse calculator that calculates primary distribution pulses obtained by distributing movement amounts in first and second directions included in a movement command of a work or a tool for each of predetermined calculation cycles. A secondary distribution pulse calculator calculates, for each movement direction, secondary distribution pulses obtained by distributing the primary distribution pulses of each calculation cycle calculated by the primary distribution pulse calculator, before and after corresponding calculation cycles within ranges of distribution sections across the corresponding calculation cycles and having an acceleration-deceleration time constant of the corresponding movement direction as a section width, and then accumulating the primary distribution pulses for each calculation cycle. A drive controller drives at least one of a tool moving device and a work moving device on the basis of the secondary distribution pulses calculated by the secondary distribution pulse calculator unit.

Claims

1. A numerical control device for a tool machine, provided at a tool machine which has a work moving device that moves a work in at least one movement direction and a tool moving device that moves a tool for machining the work in at least one movement direction, in which the movement direction of the work or the movement direction of the tool includes a first movement direction and/or a second movement direction that are different from each other, and in which an acceleration-deceleration time constant of the movement in the first movement direction and an acceleration-deceleration time constant of the movement in the second movement direction are set to mutually different values, the numerical control device serving to control a drive of at least one of the work moving device and the tool moving device, and comprising:

a primary distribution pulse calculation unit that calculates primary distribution pulses obtained by distributing individually a movement amount in the first movement direction included in a movement command of the work or a movement command of the tool and a movement amount in the second movement direction included in a movement command of the work or a movement command of the tool for each of predetermined calculation cycles;

a secondary distribution pulse calculation unit that calculates, for each of the first movement direction and the second movement direction, secondary distribution pulses obtained by distributing the primary distribution pulses of each of the predetermined calculation cycles, which have been calculated by the primary distribution pulse calculation unit, before and after corresponding calculation cycles within ranges of distribution sections across the corresponding calculation cycles and having the acceleration-deceleration time constant of the corresponding first or second movement direction as a section width, and then accumulating the primary distribution pulses for each of the respective predetermined calculation cycles; and

a drive control unit that drives at least one of the tool moving device and the work moving device based on the secondary distribution pulses calculated by the secondary distribution pulse calculation unit.

2. The numerical control device for a tool machine according to claim 1, wherein the secondary distribution pulse calculation unit calculates the secondary distribution pulses while adjusting a position of a distribution section so as to equalize a distribution amount of the primary distribution pulses in a range from a start point of the distribution section to the corresponding calculation cycle and a distribution amount of the primary distribution pulses in a range from the corresponding calculation cycle to an end point of the distribution section.

3. A numerical control device for a tool machine, provided at a tool machine which has a work moving device that moves a work in at least one movement direction and a tool moving device that moves a tool for machining the work in at least one movement direction, and in which the movement direction of the work or the movement direction of the tool includes a first movement direction and/or a second movement direction that are different from each other, the numerical control device serving to control a drive of at least one of the work moving device and the tool moving device, and comprising:

a primary distribution pulse calculation unit that calculates primary distribution pulses obtained by distributing individually a movement amount in the first movement direction included in a movement command of the work or a movement command of the tool and a movement amount in the second movement direction included in a movement command of the work or a movement command of the tool for each of predetermined calculation cycles;

a secondary distribution pulse calculation unit that calculates, for each of the first movement direction and the second movement direction, secondary distribution pulses obtained by distributing the primary distribution pulses of each of the predetermined calculation cycles, which have been calculated by the primary distribution pulse calculation unit, within ranges of distribution sections across corresponding calculation cycles and having an acceleration-deceleration time constant of a corresponding one of movement directions as a section width, and then accumulating the primary distribution pulses for each of the respective predetermined calculation cycles, and calculates the secondary distribution pulses while adjusting a position of a distribution section so as to equalize a distribution amount of the primary distribution pulses in a range from a start point of the distribution section to the corresponding calculation cycle and a distribution amount of the primary distribution pulses in a range from the corresponding calculation cycle to an end point of the distribution section;

a tertiary distribution pulse calculation unit that calculates, for each of the first movement direction and the second movement direction, a distribution error which is a difference between a primary distribution position corresponding to a position for each of the respective predetermined calculation cycles or movement according to the primary distribution pulses and a secondary distribution position corresponding to a position for each of the respective predetermined calculation cycles for movement according to the secondary distribution pulses, corrects the secondary distribution position based on the calculated distribution error, and calculates, for each of the first movement direction and the second movement direction, tertiary distribution pulses which are movement amounts of each of the respective predetermined calculation cycles, from a result of the correction; and

a drive control unit that drives at least one of the work moving device and the tool moving device on the basis of the tertiary distribution pulses calculated by the tertiary distribution pulse calculation unit.

4. The numerical control device for a tool machine according to claim 3, wherein

the tertiary distribution pulse calculation unit includes:

a distribution error calculation unit that calculates the distribution error by calculating the primary distribution position based on the primary distribution pulses, calculating the secondary distribution position on the basis of the secondary distribution pulses, and calculating a difference between these two calculated distribution positions;

an error correction pulse calculation unit that calculates an error correction pulse by using, within the distribution error calculated by the distribution error calculation unit, a first variation portion that has first variations as is, and adjusting a second variation portion that has second variations larger than the first variations such that variations thereof are relaxed; and

a distribution error correction unit that calculates a tertiary distribution position by subtracting the error correction pulse calculated by the error correction pulse calculation unit from the secondary distribution position calculated by the distribution error calculation unit and calculates the tertiary distribution pulses from the calculated tertiary distribution position.

5. The numerical control device for a tool machine according to claim 4, wherein

the primary distribution pulse calculation unit identifies in advance, based on the movement command, a calculation cycle corresponding to the first variation portion and a calculation cycle corresponding to the second variation portion within the distribution error calculated by the distribution error calculation unit, and

the error correction pulse calculation unit determines, based on the identification result by the primary distribution pulse calculation unit, the first variation portion and the second variation portion within the distribution error calculated by the distribution error calculation unit.

6. The numerical control device for a tool machine according to claim 5, wherein

when the movement command requires continuous execution of a plurality of linear movements, the primary distribution pulse calculation unit identifies a calculation cycle corresponding to the primary distribution pulse as a calculation cycle corresponding to the first variation portion when the primary distribution pulse of the predetermined calculation cycle includes a start point or an end point of a linear movement, while the primary distribution pulse calculation unit identifies a calculation cycle corresponding to the primary distribution pulse as a calculation cycle corresponding to the second variation portion when the primary distribution pulse of the predetermined calculation cycle includes neither the start point nor the end point of the linear movement.