NUMERICAL CONTROLLER HAVING TOOL LIFE MANAGEMENT FUNCTION CONSIDERING CHANGE IN MACHINING CONDITIONS

• US 20160363925A1
• Filed: 06/14/2016
• Published: 12/15/2016
• Est. Priority Date: 06/15/2015
• Status: Active Grant

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: OOHASHI, Takumi, SATO, Kazuo, MAEDA, Hideaki
• Granted Patent: US 10,222,782 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05B 19/4065 Monitoring tool breakage, life or condition
• CPC Class Codes: G05B 2219/36347 Select tool if tool life duration is sufficient for operation
• CPC Class Codes: G05B 2219/37249 Correction coefficient of life time as function of kind of machining
• CPC Class Codes: G05B 2219/37252 Life of tool, service life, decay, wear estimation

Abstract

A numerical controller determines a consumption factor representing the degree to which a tool included in a machine tool consumes the life in association with machining conditions, and calculates a tool life (accumulated consumption life) consumed before each block based on the determined consumption factor and a tool usage for each block. If a command of a block read from a machining program is a tool change command, a tool having a tool life not ending before the next tool change command is selected among tools based on the accumulated consumption life.

Claims

1. A numerical controller for machining a workpiece by controlling a machine tool including a tool based on a command of a block read from a machining program, the numerical controller comprising:

a tool data storage section for storing tool data in which the tool and a life of the tool are associated with each other;

a machining condition data storage section for storing machining condition data in which machining conditions at time of machining and a consumption factor representing a degree to which the tool consumes the tool life under the machining conditions are associated with each other;

a program operation section for controlling the machine tool based on the machining program;

a tool usage calculation section for calculating a usage of the tool for each block of the machining program;

a consumption factor determination section for determining a consumption factor by referring to the machining condition data storage section based on machining conditions at time of machining performed in accordance with the machining program; and

a life consumption-amount calculation section for calculating an accumulated consumption life, which is a tool life consumed before each block, based on the tool usage for each block calculated by the tool usage calculation section and the consumption factor determined by the consumption factor determination section,

wherein the program operation section is configured to select, if a command of a block read from the machining program is a tool change command, a tool having a tool life that does not end before a next tool change command, from among tools stored in the tool data storage section, based on the accumulated consumption life.

2. The numerical controller according to claim 1,

wherein the consumption factor determination section is configured to determines, if there is a change in machining conditions during an operation based on the machining program, a latest consumption factor based on the changed machining conditions,

the life consumption-amount calculation section is configured to recalculate an accumulated consumption life, which is a tool life consumed before each block, based on the latest consumption factor, and

the numerical controller further includes

a life exhausting block determination section for determining a block of the machining program at which a tool life of a currently-used tool will end if it is estimated, based on the recalculated accumulated consumption life, that the tool life of the currently-used tool will end before the next tool change command, and

an operation-stop-block determination section for determining a block at which a machining operation can be safely stopped in a section ranging from a block of the machining program currently executed by the program operation section to the block of the machining program determined, by the life exhausting block determination section, to be a block at which the tool life of the currently-used tool ends.