Screwer test bench with improved control

• US 10,641,671 B2
• Filed: 04/18/2016
• Issued: 05/05/2020
• Est. Priority Date: 04/22/2015
• Status: Active Grant

• Current Assignee: SCS Concept S.r.l.
• Original Assignee: SCS Concept S.r.l.
• Inventors: Boccellato, Roberto, Tinti, Carlo Giuseppe
• Primary Examiner(s): Hopkins, Brandi N
• Application Number:
  US15/564,279
• Publication Number:
  US 20180136060A1
• Time in Patent Office: 1,478 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 with a brake equipped with a fitting for a screwdriver to be tested and transducers for measurement of angle and torque, the brake being instructed by a control unit to follow, during a screwdriver test, a torque/angle curve, and the method comprising the steps of:

setting a starting Cstart torque value other than zero; and

following the torque/angle curve starting from such Cstart value.

2. The method according to claim 1, comprising the steps of:

storing, in a memory of the test bench, one or more torque/angle curves or values or points which are representative of such curves, for generation of the curves, with such curves starting from a torque value of zero and an angle value of zero;

selecting the curve to test a screwdriver;

shifting the curve in order to start from a Cstart torque with a zero angle value; and

controlling the brake according to the shifted curve.

3. The method according to claim 1, further comprising a step of controlling a route along the torque/angle curve in a bidirectional manner, the brake being controlled according to a torque/angle curve with torque values being a function of the angle during both decremental progression of the angle and incremental progression of the angle.

4. The method according to claim 3, wherein a progression of the curve is followed up to the torque/angle value set as a 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 with a brake equipped with a fitting for a screwdriver to be tested and transducers for measurement of angle and torque; and

a control unit for controlling the brake;

wherein the control unit comprises;

a memory containing at least one torque/angle curve 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. The test bench according to claim 5, wherein such test bench comprises a selection unit for the selection of a braking curve from a plurality of braking curves, the selection unit comprising:

the memory, containing one or more torque/angle curves 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 for the control of the brake according to the selected curve starting from the Cstart torque value with a zero angle.

7. The bench according to claim 5, wherein the brake is a hydraulically operated brake connected to a source of pressurized fluid via an electrically powered proportional valve controlled by the control unit.