SCREWER TEST BENCH WITH IMPROVED CONTROL

• US 20180136060A1
• Filed: 04/18/2016
• Published: 05/17/2018
• Est. Priority Date: 04/22/2015
• Status: Active Grant

• Current Assignee: SCS Concept S.r.l.
• Original Assignee: SCS Concept Italia S.R.L.
• Inventors: BOCCELLATO, Roberto, TINTI, Carlo Giuseppe
• Granted Patent: US 10,641,671 B2
• Time in Patent Office: Days
• CPC Class Codes: B25B 23/147 specially adapted for electrically operated wrenches or screwdrivers
• CPC Class Codes: G01B 21/22 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01L 25/003 for measuring torque
• CPC Class Codes: G01L 5/24 for determining value of torque or twisting moment for tightening a nut or other member which is similarly stressed

Abstract

Within a test bench for screwdrivers, comprising a braking unit (11) with a brake (14) equipped with a fitting (12) for a screwdriver to be tested and transducers (15) for the measurement of angle and torque, a method for controlling the brake (14) can include a step wherein a starting Cstart torque value other than zero is set and the torque/angle curve (17) is followed starting from such Cstart value, during a screwdriver test.

The method can also comprise a step wherein movement along the torque/angle curve (17) is controlled in a bidirectional manner, in the sense that the brake is controlled according to a curve whose torque values are based on the angle during both decremental progression of the angle and incremental progression of the angle.

Claims

1. A control method for a test bench for screwdrivers, comprising a braking unit (11) with a brake (14) equipped with a fitting (12) for a screwdriver to be tested and transducers (15) for the measurement of angle and torque, the said brake being instructed by a control unit (16) to follow, during a screwdriver test, a torque/angle curve (17), and the method comprising steps wherein a starting Cstart torque value other than zero is set and the torque/angle curve (17) is followed starting from such Cstart value.

2. A method according to claim 1, comprising a step consisting of the storage, in the memory (21) of the bench, of one or more torque/angle curves (17) or values or points which are representative of such curves, for the generation of the curves, with such curves starting from a torque value of zero and an angle value of zero, the selection of the curve to test a screwdriver, the shifting of the curve in order to start from a Cstart torque value with a zero angle value, and the controlling of the brake according to the shifted curve.

3. A method according to claim 1, comprising a step wherein the route along the torque/angle curve (17) is controlled in a bidirectional manner, in the sense that the brake is controlled according to a curve whose torque values are based on the angle during both decremental progression of the angle and incremental progression of the angle.

4. A method according to claim 3, wherein the bidirectional progression of the curve is followed to the torque/angle value set as the start of the plastic behaviour of the screw simulated by the bench with the torque/angle curve.

5. A test bench for screwdrivers comprising a braking unit (11) with a brake (14) equipped with a fitting (12) for a screwdriver to be tested and transducers (15) for the measurement of angle and torque, the brake (14) being controlled by a control unit (16) according any of the claims set out above relating to the method, the test bench comprising a memory (21) containing at least one torque/angle curve (17) or values or points which are representative of such curve for the generation of the curve, an interface for setting a Cstart value other than zero and a processing unit for the calculation—

from the curve in the memory—

of the torque/angle values to control the brake starting from the set Cstart value other than zero.

6. A test bench according to claim 5, characterised by the fact that such bench comprises a selection unit (20) for the selection of a braking curve from a plurality of braking curves, the selection unit (20) comprising a memory (21), containing one or more torque/angle curves (17) or values or points which are representative of such curves for the generation of the curves, and the processing unit—

for the calculation of a selected curve—

which is connected to the control unit (16) for the control of the brake according to the selected curve starting from the Cstart torque value with a zero angle.

7. A bench according to claim 5, characterised by the fact that the brake is a hydraulically operated brake connected to a source of pressurised fluid (18) via an electrically powered proportional valve (19) controlled by the control unit (16).