Method to check the correct functioning of a tightening tool

Patent metadata

Field	Value
Publication number	US-12571696-B2
Application number	US-202118039686-A
Country	US
Kind code	B2
Filing date	Dec 2, 2021
Priority date	Dec 3, 2020
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

Method to check the correct functioning of a tightening tool, such as an industrial screwdriver, placed on a test bench. Said bench includes a plurality of hydraulic brakes (F1-Fn), to which the instrument is associated, suitably controlled by a hydraulic circuit. Each brake is equipped with measurement transducers (TR) capable of measuring the torque exerted and the angle of rotation on this brake, connected to an electronic driver card (SP), which also controls the hydraulic circuit. The bench also includes an electronic processing unit (U) which communicates with the card and which includes an adequate driving program memorized on it capable of regulating the braking capacity of the brakes through the hydraulic circuit according to a predetermined braking torque/angle of rotation curve of the brakes. The method comprises the steps of acquiring one or more real tightening curves torque exerted/angle of rotation during one or more tightening performed for example with the tool to be tested, elaborating said real curve to make it compatible with the format of the curves that can be inserted in said test bench, supplying such one or more curves at the input to the test bench and in particular to one or more selected brakes (F1-Fn), performing a tightening with the tool on the selected brake.

First claim

The invention claimed is:

1 . A method for checking the correct functioning of a tightening tool, comprising:
placing the tightening tool on a test bench, said bench including,
a plurality of hydraulic brakes each hydraulic brake being associated with the tightening tool and being controlled by a hydraulic circuit;
each hydraulic brake comprising at least one measurement transducer configured to measure torque exerted and angle of rotation on the respective hydraulic brake, wherein each measurement transducer is connected to an electronic driver card that controls the hydraulic circuit;
an electronic processing unit configured to communicate with the electronic driver card and including a stored driving program that regulates braking capacity of the hydraulic brakes via the hydraulic circuit according to a predetermined braking torque versus angle of rotation curve;
acquiring at least one real tightening curve representing torque exerted versus angle of rotation during a tightening operation performed with the tightening tool;
processing the at least one acquired tightening curve to convert it into a format compatible with input requirements of the test bench, wherein said processing comprises at least one of: selecting a portion of the curve between a defined initial angle value and a defined maximum torque value, extending the curve at the initial and final parts, filtering torque peaks, and adapting the sampling rate;
supplying the processed tightening curve to the test bench by inputting the curve to a selected hydraulic brake; and
performing a tightening operation with the tightening tool on the selected hydraulic brake using the supplied tightening curve.

2 . The method according to claim 1 , wherein said step b) of processing the acquired tightening curve comprises selecting at least a window or a portion of said curve comprised between an initial angle value (SFA) and a maximum final torque value (T target ).

3 . The method according to claim 2 , wherein the selected portion of the tightening curve is extended in the initial part, so as to join the initial torque value and in the final part so as to arrive at a torque value configurable higher than the peak one (T target ).

4 . The method according to claim 3 , wherein said higher configurable torque value is about 10% over the peak value (T target ).

5 . The method according to claim 1 , wherein processing the acquired tightening curve comprises calculating, for each angle value in the curve, a mathematical average of all detected torque values obtained from a plurality of tightening operations.

6 . The method according to claim 1 , wherein processing the acquired tightening curve comprises, for each angle value, selecting the maximum torque value detected from a plurality of tightening operations.

7 . The method according to claim 1 , wherein processing the acquired tightening curve comprises making the sampling rate of the torque and angle values acquired by the tightening tool compatible with the sampling rate of the test bench.

Assignees

• Atlas Copco Ind Technique Ab

Inventors

• Cattaneo Massimiliano
• Celico Fadini Gianmaria
• Gerosa Roberto
• Azzone Daniele

Classifications

• G01L25/003 Primary

  for measuring torque · CPC title

• G01L3/20

  fluid actuated · CPC title

• G01L5/24 Primary

  for determining value of torque or twisting moment for tightening a nut or other member which is similarly stressed · CPC title