Method and system for conducting crash tests

• US 8,453,489 B2
• Filed: 02/29/2008
• Issued: 06/04/2013
• Est. Priority Date: 03/15/2007
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Moser, Andreas, Hofinger, Manfred, Steffan, Gundula
• Primary Examiner(s): Noori, Max
• Application Number:
  US12/530,837
• Publication Number:
  US 20100192666A1
• Time in Patent Office: 1,922 Days
• Field of Search: 73/120.1, 73/120.4, 73/120.7
• 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 mounted on a test slide which is accelerated, the acceleration force being generated by means of a reservoir (2) and applied to the acceleration object via a working piston (3) and a push rod (4),

characterized in that,

a desired gas pressure in a gas chamber (1) of the reservoir (2) is generated by the movement of a charging piston (11) exposed to the pressure of a hydraulic fluid in a charging cylinder (10);

wherein gas is stored in a gas chamber (9) separated by the charging piston (11) from hydraulic fluid in charging an oil chamber (13) of the charging cylinder (10) and wherein application of hydraulic fluid pressure to the oil chamber (13) of the charging cylinder (10) causes gas pressure to build to desired level in the gas chamber (1);

wherein upon completion of the crash test the gas is returned to the gas chamber (9) by applying hydraulic oil pressure in an oil chamber (6) of the reservoir (2) and wherein hydraulic pressure is released in charging the oil chamber (13) of the charging cylinder (10) to a hydraulic pump reservoir (16) and hydraulic pressure is applied in the oil chamber (6) of the reservoir (2) thereby displacing a moving piston (5) and evacuating gas via a discharge pipe (7) into gas chamber (9) whereby substantially all of the gas is evacuated to the charging cylinder (10) when the moving piston (5) reaches the first piston (3); and

wherein remaining hydraulic fluid in the oil chamber (6) of the reservoir (2) is forced back to the pump reservoir (16) when gas pressure is charged for the next test, gas is recirculated in a closed feedback loop and remaining gas pressure in the gas chamber (1) is recovered after the test is complete.

2. The method of claim 1 wherein the hydraulic fluid is applied by a hydraulic pump.

3. The method of claim 2 wherein the discharge pipe (7) is a tube assembly which allows free motion of the moving piston (5).

4. The method of claim 3 wherein gas is isolated in gas chamber (9) by closing valve (8), hydraulic fluid pressure is released from oil chamber (6) by valve (15) and push rod (4) is retracted to a position ready for a test.

5. The method of claim 4 wherein the hydraulic fluid is recirculated in a closed feedback loop.