FR2915579A1 - SHOCK TEST DEVICE FOR TESTING THE BEHAVIOR OF AN OBJECT DURING A SHOCK. - Google Patents

Abstract

A crash test device (1) for testing the behavior of an object (2) upon impact, comprising: - a first member (5) movable to collision with the object to be tested, and- thrust means (11) for moving the first element, characterized in that the first element (5) comprises a removable means against which the thrust means comes into contact to enable the movement of the first element and that the means thrust member comprises a first guide means (10) of a second element (8) and allows to move it until collision with the object to be tested when the removable means is deposited.

Description

The invention relates to a shock test device for testing the

  behavior of an object during a shock.

  Various types of shock tests are known to which structures can be tested. These different types of tests are implemented by different types of dedicated devices.

  In the automotive field, and more particularly in the field of automobile shock tests using large energies, there are known, for example, US Pat. No. 6,675,631 and US Pat. No. 5,483,845, impact testing devices using mobile carriages. These carriages are moved by the action of a pneumatic cylinder. The kinematic characteristics of the truck can be controlled by this pneumatic cylinder. It is also known from JP 2004-257734 a shock test catapult for launching a motor vehicle against an obstacle.

  Also known from US 2004/0103713 is a test device having a pendulum structure for subjecting vehicle parts to shocks.

  In the field of low energy impact tests, JP 2003-156421, JP 2002-318181 and JP 2006-200912 are known gravity shock test devices. In these devices, the objects are placed at a certain height above a collision surface and then released to fall on that surface.

  It is also known from JP 11-230879 a shock test device in which it is a hammer that is released from a given height and falls on a test sample. The energy of the shock C K \ 2. R44 2.12 GB R. 4 6. dpt can be adjusted by changing the height from which the hammer is released or by changing the mass of the hammer.

  EP 1615156 discloses a shock test device having a pendulum-sheep structure and equipped with a fast-action camera for studying the impacts.

  All these devices of the prior art are very specific to certain types of impact tests or to a shock energy range. They make it possible, in particular, to carry out tests under relatively fixed conditions as regards the speeds of impact, the masses put in motion and the dimensions of the samples that can be tested.

  However, in some industries, such as in the automotive industry, where there is a need for a wide range of impact tests, and in particular a range of impact tests employing highly variable energies, It is necessary to equip a wide range of testing devices or to use the services of external firms specialized in the study of shocks. Indeed, in the automotive field, impact tests must be carried out on whole vehicles, the dissipated energies are then of the order of 100 kJ. At the same time, impact tests must be carried out on insulated parts or on instrumented manikins, the dissipated energies are then of the order of 100 J. Thus, there is a need for an impact test device presenting a simple structure and allowing the realization of a wide range of shock tests in terms of dissipated energy. Such a device would significantly increase the testing capabilities of an industrial structure that would be equipped and allow the realization of more advanced tests, including the performance of instrumented tests that mobilize CK \ 2. R442.12FR.46. dpt the testing devices longer. Thus, it would be possible to better understand shock phenomena and behavior of materials subjected to shocks.

  The object of the invention is to provide a shock test device obviating the disadvantages mentioned above and improving the shock test devices known from the prior art. In particular, the invention provides a shock test device having a simple structure and allowing the realization of a wide range of impact tests, especially in terms of dissipated energy.

  The invention is more specifically based on a shock test device for testing the behavior of an object during an impact, comprising: a first element movable to collision with the object to be tested, and a thrust means for moving the first element, characterized in that the first element comprises a removable means against which the thrust means comes into contact to enable the movement of the first element and that the thrust means comprises a first guide means of a second element and allows to move it until collision with the object to be tested when the removable means is deposited.

  According to a variant, the first element comprises a recess through which the thrust means can move and in that the removable means makes it possible to close this recess.

  According to another variant, the removable means comprises a shaft provided with a shoulder and sliding in the recess until the shoulder comes into contact with the first element.

  C K \ 2. R44 2.12 F R. 4 6. dpt According to another variant, the thrust means comprises a translatable shaft whose end is intended to come into contact with the removable means or with the second element when the removable means is deposited.

  According to another variant, the first element is a carriage.

  According to another variant, the testing device comprises a second guiding means for guiding the first element in translation.

  According to another variant, the first guide means comprises a bore formed at the end of the shaft and cooperating with an extension formed on the second element, the extension being fitted sliding in the bore.

  According to another variant, the thrust means comprises a pneumatic cylinder.

  The accompanying drawing shows, by way of example, an embodiment of a shock test device according to the invention.

  Figures 1 to 3 are schematic views of an embodiment of a shock test device according to the invention shown in different phases of a shock test involving a significant energy.

  Figures 4 to 6 are schematic views of the same embodiment of a shock test device according to the invention shown in different phases of a shock test using low energy. CK \ 2. R442.12FR.46. Figure 7 is a perspective view of the carriage of this embodiment. A shock test device 1 according to the invention is described hereinafter with reference to FIGS. 1 to 6 representing it in different test phases using two impact energies. The shock test device mainly comprises a rigid frame 16, a thrust device 11, a means 13 for clamping an object 2 to

  Testing, a first element 5 movable and intended to collide with the object to be tested, a guide means 6 of the first element, a second removable element 8, displaceable and intended to collide with the object to be tested and a guide means 10 of this second element. The thrust device comprises a shaft 4 displaceable in translation in a first direction and, for example, a pneumatic cylinder 3 for moving this shaft. The shaft is mechanically linked to the cylinder. The pneumatic cylinder may, for example, be of the type described in US 5,483,845 or of the type described in US Pat.

  US 6,675,631. The end 17 of the shaft 4 is intended to come into contact with the first element or the second element in order to apply a force to it and thus to move it in the direction of the object to be tested. The thrust device is integral with the frame 16 of the testing device.

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  The clamping means 13 is also secured to the frame 16 of the testing device. It may in particular include any known means for setting in position, holding in position and clamping necessary for positioning and maintaining the object to be tested. The guiding means 6 is also secured to the frame 16 of the testing device. It guides the first element 5 in translation in the first direction. III may comprise a rail on which slides or rolls a carriage 5 constituting the first element.

  The first element 5, shown in Figure 7, comprises a bore 12 passing therethrough in the first direction. This bore is located in the axis of the shaft 4 and has a diameter greater than that of the shaft. Thus, the shaft can move freely through the first element 5. The bore 12 and the shaft 4 are for example cylindrical of revolution. The displacement of the shaft 4 through the first element may however be prohibited by a removable means 7 closing the bore 12. This means consists for example of a cylinder 14 of diameter smaller than that of the bore, this cylinder comprising a shoulder 15 abutting against a face 18 of the first element 5. As seen above, when positioned on the first element, the displacement of the shaft is prohibited in the bore. Thus, the end 17 of the shaft comes into contact with a face 19 of the removable means and can move the first element 5 by applying a mechanical action on it.

  Shock tests requiring high energies are performed with the test device configured with the removable means in position on the first element. A test of this type is for example shown in Figures 1 to 3. In Figure 1, the shaft 4 is retracted, in an initial position, at a standstill and in contact with the removable means in position on the first element. In Figure 2, the shaft 4 has left its initial position and is moving. It drives in motion the first element 5 by the mechanical action that it exerts on it. In Figure 3, the shaft 4 has arrived at the end of the race. He is immobilized in the deployed position.

  However, the first element is still moving due to C K \ 2. R442.12 EN.46. dept the energy that the tree gave him 4 and because of its inertia. The first element is: about to collide with the object to be tested.

  The shaft 4 comprises at its end the guiding means of a second removable element 8, displaceable and intended to come into collision with the object to be tested. The guiding means allows the translational guidance of the second element in the first direction. The guide means comprises a bore 10. It is intended to cooperate with an extension 9 made on the second element. This extension consists for example of a cylindrical shaft of diameter less than that of the bore 10. Thus, the second element is mounted or adjusted sliding in the bore 10.

  Shock tests requiring low energies, are carried out with the test device configured with the removable means deposited and with the second removable element 8 placed in position at the end of the shaft 4. A test of this type is by As shown in Figures 4 to 6. In Figure 4, the shaft 4 is retracted, in an initial position, at a standstill and in contact with the second element. The first element 5 has been moved to the end of the race opposite to the object to be tested. Thus, the shaft 4 passes through the first element. In Figure 5, the shaft 4 has left its initial position and is in motion. It drives in motion the second element 8 by the mechanical action that its end 17 exerts on a face 20 of the second element. In Figure 6, the shaft 4 has arrived at the end of the race. He is immobilized in the deployed position. However, the second element is still moving because of the energy that the tree 4 has given it and because of its inertia. The second element is guided by the cooperation of the bore 10 and the extension 9 and is about to collide with the object to be tested.

  C K \ 2. R442.12 E R.4 6. dpt The use of the first element or the second element to test the object allows the realization of impact tests using energies varying in a wide range. For example, the first element may consist of a trolley having an area of between 350 kg and 1000 kg. The use of such an element makes it possible to cover a range of shock energies ranging from 5 kJ (approximately equivalent to 350 kg projected at 5 m / s) to 100 kJ (approximately equivalent to 1000 kg projected at 14 m / s ).

  For example, the second element may consist of a mass of between 10 kg and 50 kg. The use of such elements makes it possible to cover a range of impact energies ranging from 100 J (approximately equivalent to 10 kg projected at 5 m / s) to 6 kJ (approximately equivalent to 50 kg projected at 15 m / s). CK \ 2.R442.12FR.46.dpt

Claims (8)

claims   A shock test device (1) for testing the behavior of an object (2) upon impact, comprising: a first member (5) movable to collision with the object to be tested, and a thrust means (11) for moving the first element, characterized in that the first element comprises a removable means (7) against which the thrust means comes into contact to enable the first element to move and the means thrust member comprises a first guide means (10) of a second element (8) and allows to move it until collision with the object to be tested when the removable means is deposited.   2. Test device according to the preceding claim, characterized in that the first element comprises a recess (12) through which the thrust means can move and in that the removable means allows to close this recess.   3. Test device according to the preceding claim, characterized in that the removable means comprises a shaft (14) provided with a shoulder (15) and sliding in the recess until the shoulder comes into contact with the first element. 25   4. Test device according to one of the preceding claims, characterized in that the thrust means comprises a shaft (4) movable in translation whose end is intended to come into contact with the removable means (7) or with the second element 30 when the removable means is deposited. CK \ 2.R442.12FR.46.dpt20   5. Test device according to one of the preceding claims, characterized in that the first element is a carriage.   6. Test device according to one of the preceding claims, characterized in that it comprises a second means (6) for guiding the first element in translation.   7. Test device according to one of the preceding claims, characterized in that the first guide means comprises a bore (10) formed at the end of the shaft and cooperating with an extension (9) formed on the second element, the extension being adjusted sliding in the bore.   8. Test device according to one of the preceding claims, characterized in that the thrust means comprises a pneumatic cylinder (3). C K \ 2. R442.12FR.46. filing