SU1659875A2 - Arrangement for testing products under dynamic loads - Google Patents

Abstract

The invention relates to testing equipment, in particular to centrifugal test benches, and can be used in design development and in the production process of devices exposed in real operating conditions to pulses of angular acceleration of speed. The aim of the invention is to expand the functional and operational capabilities by increasing the amplitude and steepness of the trailing edge of the generated acceleration pulse. The goal is achieved by the fact that a spindle 8 braking device is additionally located on the stand. After a signal is given to the electromagnet 12, the spindle 8 is released, which, under the action of a load of goods 6 wound up by means of a flexible link 6, flying along the guides 4 to the periphery, receives an increasing impulse educational acceleration. Upon reaching the periphery, the cargo 5, through the hydraulic system 14, 13, 21, 16, 17, activates the braking system, which engages the braking element 19 and the friction element 23 and ensures the implementation of the trailing edge of the acceleration pulse. The parameters of the reproduced angular acceleration pulses are adjusted by varying the angular velocity of the platform 2 and the mass of the weights 5, as well as by the adjustable throttle of the drain line 21. 1 Cp f-ly, 2 ill.

Description

The invention relates to testing equipment, in particular, to centrifugal test stands, and can be used for testing during design development and in the production process of devices exposed to actual acceleration pulses (speed) under actual operating conditions.

The purpose of the invention is to expand the functional and operational capabilities by increasing the amplitude and steepness of the trailing edge of the generated acceleration pulse.

Figure 1 shows the stand, a general view; figure 2 - the reproduced angular momentum

speed (dotted - the same before improvement).

The bench contains a platform 2 mounted on a fixed base 1 with a drive 3 of its rotation. On platform 2, guides 4 are radially fixed, on which movable elements 5 are connected, connected by flexible coupling 6 to spindle 8 mounted on supports 7. Spindle 8 is fixed to table 9 for accommodating the test article 10. Spindle 8 is coupled to platform 2 of coupling 11, controlled by an electromagnet 12. At the periphery of the platform 2, there is a braking device, including a power cylinder 13, a piston 14 placed in it with a rod 15,

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facing the moving elements (weights) 5, the second cylinder 16, the piston 17 placed therein with a rod, 18, having a brake element 19 at the end, mounted in the guide 20, and a drain line 21 connecting the cavity of the power cylinder 13 and the second cylinder 16. On the surface of the brake element 19 facing the spindle 8, a friction element 22 is fixed, which interacts during braking of the spindle 8 with a circular friction element 23 mounted on the spindle 8. In the initial position, the piston 14 is pressed to the end wall 24 of the cylinder 13. At the periphery 2 platform near the wall 24 is mounted a resilient member 25 for braking the movable member. Line 21 may be equipped with a hydraulic valve, throttle and a device for draining excess liquid (not shown).

The stand works as follows.

The test article 10 is installed on the table 9, the flexible connection is wound on the spindle 8, the moving elements 5 are mounted at a minimum distance from the center of rotation of the platform 2. The spindle 8 is coupled by the coupling 11 with the platform 2, After turning on the drive 3, the platform 2 accelerates to the calculated angular velocity, which depends on the required dynamic effects.

Under the action of centrifugal forces, the piston 17 with the rod 18 moves to the periphery of the platform 26, creating an overpressure in the cylinders 13 and 16, under the action of which the piston 14 presses against the wall 24 (therefore the diameters of the cylinders 13 and 16 are equal;

the ends distant from the platform axis are placed at equal distances from the axis of rotation of platform 2, the mass of the piston 17 with the rod 18 is greater than the mass of the piston 14 with the rod 15, the volume of fluid poured into the hydraulic system is equal to two volumes of the cylinder 13 and the volume of the trunk 21). After that, the device is ready for testing.

Next, using an electromagnet 12, the coupling 11 is disconnected, freeing the spindle 8. Under the action of centrifugal forces, the movable elements 5 move to the periphery of the platform 2, move progressively along the guides 4, convert through the flexible coupling 6 progressive translation into the angular rotation of the spindle 8 relative to the platform 3, while the spindle and the table with the product under test rotate with acceleration.

The length of the flexible connection is chosen in such a way that, when the load touches the stock 5

flexible communication is disconnected. When the load 5 interacts with the rod 15 as it moves toward the periphery of the platform 2, the piston 14 moves synchronously with the load 5, causing the piston 17 to move to the axis of rotation of the platform 2 and the friction elements 23 and 22 enter into interaction. The spindle 8 brakes. In this case, the product is affected by the acceleration impulse of the opposite sign. Further, the load 5 is braked by the elastic element 25, while the piston 14 does not reach the end of the cylinder 13 to avoid impact due to the parameters of the brake elastic element 25 and the length of the rod 15. The parameters of the reproducible pulses of the angular acceleration of the positive sign can be changed by varying the angular velocity of the platform 2 and the mass loads 5. Parameters of angular acceleration pulses

the negative sign can be changed by adjusting the braking modes; for this, the line 21 can be equipped with an adjustable choke, which changes the resistance to the outflow of fluid from the cylinder 13

into the cylinder 16, and hence the deceleration time of the spindle 8 relative to the platform 2.

Claims (2)

1. Stand for testing products on the impact of dynamic loads on av.st. Kb 1158939, characterized in that, in order to expand the functional and operational capabilities by increasing the amplitude and steepness of the falling front of the acceleration pulse, the stand is equipped with a spindle braking device mounted around the periphery of the platform and containing the first power a hydraulic cylinder with a piston and a rod facing the moving elements of the platform, a second hydraulic cylinder with a piston and a rod having, at the end facing the spindle, a braking element mounted in the guide and a drain line connecting the cavities of both cylinders, while one against the other surfaces of the braking element and the spindle there are installed friction elements placed with the possibility of interaction with each other when braking the spindle. 2. A stand according to claim 1, characterized in that the drain line is equipped with an adjustable throttle, the diameters of the cylinders and the masses of the pistons are equal, and the working cavities are at equal distances from the axis of rotation of the platform. BP5 # g 18 4- (5 25 ft 13 FIG. 2 Compiled by G. Ermolaev Editor L. Veselovska Tehred M. Morgental Corrector E. Lonchakova Order 1840 Circulation 348 Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk emb. 4/5 Production and Publishing Combine Patent, Uzhgorod, Gagarin st., 101