SU1550338A1 - Method of determining dynamic forces - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure dynamic forces in joints. The aim of the invention is to improve the accuracy. This is achieved by installing between the connections in series with the first force sensor 2 of the circular cylinder 4 and the second force sensor 5. At the same time, an acceleration sensor 3 is installed on the cylinder, the created force is affected by the dynamic force, the acceleration amplitude and phase angles of oscillations of the force vectors are measured, and the dynamic force is determined by the formula given in the description text of the invention.

Description

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The invention relates to a force engineering technique and can be used to measure dynamic forces in joints.

The aim of the invention is to improve the accuracy.

FIG. 1 shows a scheme for implementing the method; in fig. 2 - a device that implements the method.

Let force sensors with a known mass M fixed between them be installed between the paw of the mechanism and the vibration isolator (see Fig. 1), where 1 is the paw of the mechanism: reference link; 2 — dynamic force sensor F (; 3 — oscillatory acceleration sensor; 4 — known is the mass of the circular cylinder;

5- dynamic force sensor FJ,;

6- vibration isolator; 7 - the foundation.

Distinctive features of the method are the installation under the force sensor of an additional force sensor with the placement between them of a known mass M, measurement of the amplitude and phase angle of the vector of oscillatory acceleration of this mass, as well as the phase angles of the dynamic force vectors acting on the force sensors and formula:

F M.a.§i2life -J & l

sin (CfFl -4V,)

where a is the amplitude of the vector a of the oscillatory acceleration of a known mass, m sG;

Cf is the phase angle of vector a, degrees; tf p, phase angles of the dynamic force vectors FJ and F4 acting on the upper and lower force sensors, respectively, degrees;

11 - known mass, kg. The method of measuring dynamic forces can be implemented by a measuring sensor shown in FIG. 2, The device consists of a body 3, of known mass, made in the form of a straight circular cylinder, in the upper and lower bases of which, coaxially with its axis, are installed bimorph piezoceramic elements 9 and 10, closed by covers 11 and 12 and having pins 13 and 14. In the cylindrical niche of the housing 15, which is closed on the side of the upper base of the housing, a screw plug 16 is fitted with an inertial element 17 on

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piezoelectric elements 18, mounted on a flat niche base, having pin 19 and producing an electrical signal proportional to the acceleration of the body.

The device works as follows.

. The housing 8, having made an oscillatory motion under the influence of a working mechanism, excites the oscillatory motion of the inertial element 17, which causes the generation of an electrical signal by piezoelectric elements 18, mounted on a flat base of a cylindrical niche 15, which is closed from the upper base of the housing by a screw stopper 16. Generated by piezoelectric elements 18, proportional to the acceleration of the housing 8, is removed from pin 19 to the input of the measuring apparatus. Vibrational displacement of the housing 8 relative to the covers 11 and 12 cause deformation of the bimorph piezoceramic elements 9 and 10, leading to the generation of electrical signals proportional to the dynamic forces acting on them, taken from the terminals 13 and 14 to the inputs of the measuring equipment.

Claims (1)

Invention Formula The method of determining the dynamic forces, which consists in setting up a force transmitter between the support and non-support links, is characterized in that, in order to increase the accuracy, between the connections, the inertial mass and the second force sensor are measured in series with the first force sensor the acceleration amplitude and phase angles of oscillations of the force vectors, and the magnitude of the dynamic force is determined by the formula F „.а. ™ & Ј - Str.1 F sin (q Fl-tfF () where M is the known mass of the circular cylinder; a is the amplitude of the vector of oscillatory acceleration of a circular cylinder; Cpq is the phase angle of the acceleration vector; H and CfF are the phase angles of the dynamic force vectors, F ,, and P2, acting on the force sensors. at to Vt / g. 2 to go