US 12,275,110 B2
Method for detecting the wear of a milling cutter of a key-duplicating machine
Gennaro Giovanni Nigro, Mareno di Piave (IT); Maurizio Ugel, Cordenons (IT); and Giorgio Pigatti, Cordignano (IT)
Assigned to SILCA S.P.A., Vittorio Veneto (IT)
Appl. No. 17/772,984
Filed by SILCA S.P.A., Vittorio Veneto (IT)
PCT Filed Oct. 30, 2020, PCT No. PCT/IB2020/060195
§ 371(c)(1), (2) Date Apr. 28, 2022,
PCT Pub. No. WO2021/084487, PCT Pub. Date May 6, 2021.
Claims priority of application No. 102019000020168 (IT), filed on Oct. 31, 2019.
Prior Publication US 2024/0149384 A1, May 9, 2024
Int. Cl. G05B 19/4065 (2006.01); B23C 3/35 (2006.01); B23Q 17/09 (2006.01)
CPC B23Q 17/0995 (2013.01) [B23C 3/35 (2013.01)] 12 Claims
OG exemplary drawing
 
1. Key-duplicating machine with at least one milling device (11) comprising:
at least one cutter (4) which is provided with cutting sections (8) to obtain the bitting cuts on a key (3),
an electric motor (5) to cause the rotation of said cutter (4),
at least one processor which is electronically connected to said electric motor (5) for the control and command of the electric motor,
at least one instrument that is configured to detect at least one of: a current (I) or voltage (V) absorbed or required by said cutter (4) rotation motor (5) during at least one cutting cycle carried out by said cutter (4), and to send at least one of: values or signals thus detected to said at least one processor,
and said at least one processor is configured to implement a method for detecting wear of said cutter (4), said method comprising:
detecting, during at least one cutting cycle carried out by said cutter (4), at least one of: values of current (I) or voltage (V) absorbed or required by said motor (5) for rotation of cutter (4) or motor torque values (C) exerted by said motor (5);
calculating, based on the values thus detected, an energy absorbed by said motor (5) of rotation of the cutter (4) and at least one of: determining, on the basis of the energy thus calculated, if there is wear of the cutting portions (8) of said cutter (4) or quantifying the wear of the cutting portions (8) of said cutter (4);
calculating the energy absorbed by said motor (5) during all subsequent cutting cycles carried out with said cutter (4) using a counter (ETA) which is initialized at the beginning of the useful life of the cutter (4) and which is then correspondingly increased with the energy absorbed by said motor (5) of rotation of the cutter (4) during each cutting cycle carried out with said cutter;
recording characteristics of the current absorption peaks (I) by the motor (5) of rotation of the cutter (4) during at least one cutting cycle,
comparing the energy thus calculated with at least a predefined threshold value (ETH) and the characteristics of said peaks are used to at least one of: determine if there is wear of the cutting portions (8) of said cutter (4) or to quantify wear of the cutting portions (8) of said cutter (4),
and wherein said at least one processor is configured to implement a method wherein the total accumulated value ETA is compared with the predetermined threshold value ETH and also the amplitude of the absorbed current peaks (AP) by the motor (5) and/or the torque C exerted by said motor (5) during that determined cutting cycle is compared with a corresponding predetermined threshold value ATH-P and following said comparison:
the condition in which ETA is greater than or equal to ETH and in which AP is greater than or equal to ATH-P, a state of wear of the cutting sections (8) of said cutter (4) is associated, which is therefore to be replaced;
while to the condition in which ETA is lower than ETH, or to the condition in which AP is lower than ATH-P even if ETA is greater and/or equal to ETH, a state is associated in which the cutting portions (8) of said cutter (4) are still efficient, and therefore it is not necessary to replace the cutter.