SU1422044A1 - Resonator for vibration testing machine - Google Patents

Abstract

This invention relates to a technique for vibration testing of articles. The purpose of the invention is to expand the operational capabilities of the resonator by creating an asymmetric loading cycle of the test product-g. Such a cycle is obtained due to a full resonator in the form of a beam with three parallel branches and applied to the central working branch, having a cross section in the form of a trap, elastic force , side branches 2 and 3 using screws 6 and 7 screwed into the last, the ends of which are in contact with the lateral faces of the working branch 1. The elastic forces are different when the branch 1 is upward and intrinsic from the position of Noves. To eliminate oscillations of the side branches, the proper frequency of each of them lies in the resonance region of oscillations of the working branch. and

Description

f1 / g

; The invention relates to a testing technique, in particular, to vibration testing of products, namely, resonators for vibration stands,

The purpose of the invention of pacurapem-ie, the operational capabilities of the resonator due to the creation of an asymmetric cycle of loading the test product

- On fng, 1 shows the proposed resonator, top view; in figure 2 - then, the view, view s.perer, and | FIG. 3 is a section on fiFo2 in FIG. 4, the diagram of the actual forces, on their working branch of the iB-beam down position; in Figure 5, then me is in the upper position.

The resonator is a dbdoft beam with three parallel branches;

having

the central working branch in the section-1 and the shape of the trapezium (Fig. 3), and the lateral branches 2 and 3 located symmetrically with respect to the longitudinal axis of the balkn. At the ends of the beams there are supporting points 5 4 with holes - 5 ,. the following; to install the beam on the table around an enclosure (not shown) “In the central parts of the lateral branches 2 and

3 screws 6 and 7 are screwed, the ends of which are in contact with the lateral faces of the working branch o To increase the area: the contact on the side faces can be made with semicircular grooves 8 "You can choose from the side branches 2 and 3 such that the frequency of the side branch lay in the dawn of the oscillation region of oscillations of the working branch,. To install the test product on the working branch 1, it is advisable to perform a protrusion 9,

The resonator works in the following manner.

When the vibration frequency of the vibrating bench table is equal to the natural frequency of the working branch 1 of the beam, its resonant co-vibrations are excited, while the side branches 2 and 3 due to their higher natural frequencies, not the resistor, therefore, the working branch 1 is shifted relative to the side branches 2 and 3, acts on the side edges of the screws 6 and 7, which leads to the deformation of the side branches 2 and 3. When the beam moves up and down from the equilibrium position, it is affected by various elastic forces of the side branches 2 and 3 tightening screws b 7 i.sily friction. The resultant force F acting on the working branch of 1 beam in the lower

) S

0

five

0

five

0

five

0

five

position, is equal to F, F, - 2 F® - 2 F "cosa, and the resultant force F, acting on the working branch 1 in the upper position, is 2 F - - 2 FTP - coso 5 where F is the inertia force s Fg, - vertical component of the force Fg, applied to the working branch

1 with CTOpoitti of the screw, the friction force ,, yC - the angle between the vertical and the side edge of the working branch.

In the extreme upper position of the working branch 1 deflection of the side branches

2 and 3 is minimal, and in the lowest position - maximum.

The cycle asymmetry factor is determined by the ratio of the forces F, and - - FJF,

For a resonator made of steel 45 with v1-filling of the working branch with an average width of 60 mm, height of 6 mm, width and height of the side branches, respectively, 10 and 11 mm, angle oL 20 °, weight of the device with a test piece of 0.5 kg And the maximum acceleration with a symmetric cycle equal to 300g, the coefficient of asymmetry of the cycle is - OjlS. This coefficient can be adjusted within small limits by varying the tightening forces of the screws. When the latter are derived from the interaction with the work branch, a symmetric loading cycle is obtained.

Claims (1)

Invention Formula A vibrostand resonator, which is a beam with supporting protrusions W at the ends, serving to set the baffles on the table of the vibrostand, distinguished by 4TOj with the aim of expanding the operational ones; possibilities by creating an asymmetric loading cycle of the tested product, the beam is made with three parallel branches, the central working branch section has the shape of a trapezoid, in the central parts of the side branches symmetrically located relative to the longitudinal axis of the beam, screws are screwed, the ends of which are in contact with the side edges working vatvi, while the natural frequency of each of the lateral branches of the beam lies in the resonance region of oscillation of the working branch. .a g / V F1 / g.Z. F1 / g.1 fig a Editor A. Shandor Compiled by V. Shakhter Tehred M. Morgental Proofreader L. Patay Order 4418/39 . Circulation 847 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 5 Subscription