METHOD AND SYSTEM FOR CONDUCTING CRASH TESTS

• US 20100192666A1
• Filed: 02/29/2008
• Published: 08/05/2010
• Est. Priority Date: 03/15/2007
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Moser, Andreas, Steffan, Gundula, Hofinger, Manfred
• Granted Patent: US 8,453,489 B2
• Time in Patent Office: Days
• US Class Current: 73/12.04
• CPC Class Codes: G01M 17/0078 Shock-testing of vehicles

Abstract

The invention relates to a method for conducting crash tests in which an object, in particular a motor vehicle or part of a motor vehicle, is typically mounted on a test slide which is accelerated, the acceleration force being generated by means of a pressurized-gas reservoir and specifically applied to the acceleration object via a piston and a push rod, while for reducing the cycle times, the desired gas pressure in the pressurized-gas reservoir is generated by moving a piston, itself exposed to a hydraulic fluid, so as to apply pressure on the gas. The invention also relates to a correspondingly implemented system.

Claims

1. Method for conducting crash tests in which an object, in particular a motor vehicle or part of a motor vehicle, is typically mounted on a test slide which is accelerated, the acceleration force being generated by means of a pressurized-gas reservoir (2) and specifically applied to the acceleration object via a piston (3) and a push rod (4),

characterized in that

the desired gas pressure is generated in the pressurized-gas reservoir (2) by the movement of a piston (5) acting on the gas and itself exposed to the pressure of a hydraulic fluid.

2. Method as in claim 1,

characterized in that

the hydraulic fluid is applied by a hydraulic pump.

3. Method as in claim 2,

characterized in that

the necessary gas supply is provided in a particular, separate piston chamber (10)[sic] which on one side of the piston (11) contains the gas and on the other side contains the hydraulic fluid.

4. Method as in claim 1,

characterized in that

upon completion of the crash test the gas is returned to the gas reservoir i.e. piston chamber (9).

5. Method as in claim 1,

characterized in that

the gas is returned by the movement of an additional piston (5) contained in the pressurized-gas reservoir (2), which movement is brought about by the hydraulic fluid.

6. Method as in claim 1,

characterized in that

the hydraulic fluid is applied by the same hydraulic pump (16) that delivers the hydraulic fluid for generating the gas pressure.

7. Method as in claim 6,

characterized in that

the additional piston (5) is returned to its home position by the retraction of the push rod (4).

8. Method as in claim 1,

characterized in that

the gas recirculation takes place in a closed feedback loop.

9. Method as in claim 1,

characterized in that

the hydraulic-fluid recirculation takes place in a closed feedback loop.

10. Method as in claim 1,

characterized in that

the hydraulic-fluid circulation system includes a hydraulic-fluid reservoir (16).

11. Method as in claim 1,

characterized in that

the gas employed is nitrogen.

12. Method as in claim 1,

characterized in that

the inertial deceleration forces of a real collision are simulated by accelerating the test object along the real inertial deceleration curve.

13. Method as in claim 12,

characterized in that,

during the crash test using the test slide, a force is applied in the direction of acceleration that is greater than the force needed for an acceleration corresponding to the real inertial deceleration curve, and that for attaining the desired acceleration curve, the crash test slide, or a device driving it, is exposed to a braking force having a vector opposite the direction of acceleration, which braking force is strong enough to cause the resulting force to accelerate the slide along the desired acceleration curve.

14. System for conducting crash tests in which an object, in particular a motor vehicle or part of a motor vehicle, is typically mounted on a test slide which is accelerated, said system comprising a pressurized-gas reservoir (2) for generating the acceleration force that is specifically applied to the acceleration object via a piston (3) and a push rod (4),

characterized in that

a piston-and-cylinder assembly (10) is provided, with a piston (11) that subdivides the cylinder (12) into a first piston chamber (9) that accepts the pressurized gas, and a second piston chamber (13) that accepts the hydraulic fluid, and that the second piston chamber (13) can be filled with a hydraulic fluid serving to move the piston (11).

15. System as in claim 14,

characterized in that

the second piston chamber (13) connects to a hydraulic-fluid reservoir via a hydraulic pump.

16. System as in claim 15,

characterized in that

the piston-and-cylinder assembly (10) is configured as a separate piston-type accumulator, and that the first piston chamber (9) connects to the pressurized-gas reservoir (2) via a pressure conduit (7).

17. System as in claim 16,

characterized in that

the pressurized-gas reservoir (2) is provided with an additional piston (5) by means of which the gas can be returned from the pressurized-gas reservoir (2) into the piston-chamber gas reservoir (9).

18. System as in claim 17,

characterized in that

the additional piston (5) subdivides the pressurized-gas reservoir (2) into a first piston chamber (1) for the gas and a second piston chamber (6) which latter can be filled with a hydraulic fluid for moving the piston (5).

19. System as in claim 18,

characterized in that

the second piston chamber (6) connects to the hydraulic-fluid reservoir via the same hydraulic pump.

20. System as in claim 19,

characterized in that

by retracting the push rod (4) the additional piston (5) can be returned to its home position;

whereas

the gas is recirculated in a closed feedback loop;

the hydraulic fluid is recirculated in a closed feedback loop; and

the gas employed is nitrogen.

21. (canceled)

22. (canceled)

23. (canceled)