SU44371A1 - Fatigue Testing Machine - Google Patents

Description

The proposed machine is designed to test yarns and fabrics for fatigue.

In FIG. 1 shows a diagram of the device of the proposed machine and FIG. 2 — a device of a drum spring of a writing device, through a conventional quadrant rotating near the axis / (Fig. 1), a chain is thrown, to the lower end of which a top clip 2 of the machine is attached. The lower clamp 3 receives movement from the motor by means of a worm gear, by means of which a very low speed can be achieved. The horizontal worm to 4, receiving movement from the motor through a belt drive, drives the worm gear 5. It has in the inner surface of the hub, through which the vertical screw 6 is passed, cutting, through which the screw 6 has the ability to move along its axis, the lower clamp 3. The clamp 3 moves in the guides 23, 24.

To the traverse of the lower clamp at the point / attached cord, thrown over two blocks, one of which (horizontal) rigidly sits on the same axis with the drum 8 recorder.

On the axis of rotation / quadrant the eccentric 9 of the special profile is rigidly set. Attached to it is a cord coming from the writing device 10 and thrown over the path through the guide roller / 7.

The recording is as follows. When the lower clamp 3 moves down (load), the drum / O will have a peripheral speed proportional to the lower clamp movement speed and time, since the motor speed can be considered constant. Moving the writing pen in the vertical direction will be proportional to the load due to the eccentric R. Thus, we obtain the curve (t) After processing this curve, it will be easy to obtain the (-) curve (dependence of the load on the elongation). When the upward movement of the clamp 3 (unloading), the drum with the help of a spiral spring located inside it (Fig. 2) will have a reverse movement, as a result of which the unloading diagram is recorded in the same axes of coordinates.

To test the yarns and fabrics for fatigue, the crosshead of the lower clamp 3 has an additional sleeve 12, inside which a ha is missed 14. When the clamp moves down, the sleeve / 2 encounters an emphasis 15 on its way, causing the ri 14 to go down. The articulated parallelogram 76, connected to the thrust 15, serves as a reversing mechanism and converts the belts (open and cross) to another pair of pulleys (idle and working), thereby forcing the reversing movement of the clamp 5. To reverse the course, the sleeve 72 uses the stop 77 will move the tractor up and transfer the belts to the previous pulleys (idle and working), etc. The movement can repeat as long as necessary, up to the final breaking of the material, and during the whole test the drum will record itself load and discharge curves. In addition, the appendix 18 in its path touches the counter 19, marking the number of repeated loads.

The distance between the stops 15 and 77 can be set as desired. This ensures that the material is tested within any load.

When testing material for fatigue, there is no need for the experimenter himself to be present near the dynamometer, since after breaking the material the quadrant by inertia force deviates somewhat beyond the zero position (shown in dotted lines) and the protrusion 20 on the quadrant deflects the lever 21, after which the spring connected by a flexible link with a switch or with any other switch off, the current by means of it, will stop the supply of current to the motor, and the aatOMafH dynamometer will stop working. The writing device will show the moment of rupture without an automatic stop, but we could not have known the number of repeated loads without the experimenter’s personal absence. The reserve of the kinetic energy of the quadrant when it falls after a break is partially absorbed by the impact of the protrusion 20 on the lever 21 and, moreover, buffer 22 is also provided so that the impact point falls at the center of the impact of the quadrant, which is easy to determine with ordinary ratschetsy.

The subject matter of the invention.

Claims (2)

1. A machine for testing fatigue threads and fabrics, in which one of the clamps for the test specimen is connected to a dynamometer, and the other with a mechanism for creating stresses, characterized in that the mechanism for creating stresses is equipped with a device for automatically reversing it the purpose of periodically weakening and reinforcing stresses. 2. In a machine according to claim 1, use a rod with a sleeve 72, rigidly fastened to a voltage-generating mechanism, with the purpose of acting on adjustable stops 75 and 77 of the rod 14 connected with a reversing mechanism. to the author's certificate of I. V. Sergevnin № 44371  Fig1 Ij.-VN / V WX / V. ™ W./////////