APPARATUS AND METHOD FOR DETECTING DAMAGE TO TOOL IN MACHINE

• US 20130253670A1
• Filed: 11/01/2011
• Published: 09/26/2013
• Est. Priority Date: 12/09/2010
• Status: Active Grant

• Current Assignee: DN Solutions Company Limited (DN AUTOMOTIVE Corp.)
• Original Assignee: Doosan Infracore Company Limited
• Inventors: Chung, Dae Hyuk, Sung, Dae Jung
• Granted Patent: US 9,760,083 B2
• Time in Patent Office: Days
• US Class Current: 700/79
• CPC Class Codes: B23Q 17/0961 by measuring power, current or torque of a motor
• CPC Class Codes: G05B 19/4065 Monitoring tool breakage, life or condition

Abstract

The apparatus for detecting damage to the tool in the machine and the method of detecting damage to the tool according to the present disclosure are applied to a machine, such as a CNC, to detect and control damage to a tool and possibility of damage in advance, thereby efficiently managing processing work by the machine while achieving safety of the machine.

Claims

1. An apparatus for detecting damage to a tool in a machine, comprising:

a detector configured to receive a current signal according to torque from a servo and a spindle of a machine;

a simulator configured to calculate a prior processing condition by using information input from a numerical controller of the machine;

a tool DB configured to store a torque value measured at the time of prior processing of a currently mounted tool and information on a processing condition;

a tool manager configured to record the torque value measured at the time of the prior processing by the currently mounted tool and a corresponding tool and the information on the processing condition in the tool DB or extracting information from the tool DB;

a critical torque calculator configured to receive information recorded in the tool DB from the tool manager, and calculate a range of torque predicted to be generated during processing work by using the prior processing condition calculated by the simulator;

a critical torque data storing unit configured to store an upper limit value and a lower limit value of the torque predicted by the critical torque calculator;

a comparator configured to compare the torque measured by the detector and a critical torque range from the critical torque calculator; and

a controller configured to control a processing operation of the machine according to a result of the comparison by the comparator.

2. The apparatus of claim 1, wherein the machine processing operation controller comprises:

a tool damage prevention unit configured to control so that the machine is operated under an adjusted processing condition by controlling the machine to adjust a rotation speed or a feed of a workpiece so as to prevent abrasion of the tool from exceeding a predetermined value when measured torque approaches a threshold value within a first reference value;

a tool damage prediction unit configured to warn a driver of the machine through an alarm means so as to allow the driver of the machine to take measures, such as replacing the tool or changing the processing condition when the measured torque approaches the threshold value within a second reference value smaller than the first reference value; and

a tool damage detection unit configured to stop the processing operation of the machine by controlling the numerical controller when the measured torque is out of the threshold value.

3. The apparatus of claim 1, wherein the tool DB sets pot information of a tool magazine and a material of the workpiece as a pair of elements of reference information, and torque information actually measured under a processing condition, such as a depth of cut and a feed, for the pair of elements of reference information is stored as one set.

4. A method of detecting damage to a tool in a machine, comprising the steps of:

(A) receiving a current signal according to torque from a servo and a spindle of a machine;

(B) calculating a prior processing condition by using information input from a numerical controller of the machine;

(C) adding a new tool to be used in processing and setting tool information;

(D) calculating a range and a threshold value of torque predicted to be generated during processing work by using the information stored in step (C) and the prior processing condition calculated in step (B), and storing the range and the threshold value of the torque as necessary;

(E) comparing the torque measured in step (A) with the range and the threshold value of the torque calculated in step D; and

(F) controlling a processing operation of the machine according to a result of the comparison in step (E).

5. The method of claim 4, wherein in step (F), a mode for controlling the processing operation includes a tool damage detection mode, a tool damage prevention mode, and a tool damage prediction mode, and

in the tool damage prevention mode, when it is determined that the current torque detected in step (A) approaches a threshold value calculated in step (D) within a first reference value, an operation of the machine is controlled so that the processing condition, that is, a depth of cut and a feed, is changed, so as to prevent the tool from being damaged,

in the tool damage prediction mode, when it is determined that the current torque detected in step (A) approaches the threshold value calculated in step (D) within a second reference value smaller than the first reference value, it is determined that there is a concern regarding generation of damage to the tool, so that a warning is generated through an alarm means, and

in the tool damage detection mode, when the current torque detected in step (A) exceeds the threshold value calculated in step (D), it is determined that the tool damage is generated, the machine is controlled so as to stop the operation of processing work so as to prevent the machine from being damaged.