RU1770789C - Scales for hydrodynamic pipes - Google Patents

Abstract

SUMMARY OF THE INVENTION: the balance comprises elastic measuring elements placed in a cylindrical body with strain gauges, wrapped in a thin-walled flexible shell of elastic material, the cavity of which is filled with a neutral liquid. 11 ill.

Description

The invention relates to experimental hydrodynamics, in particular to tensometric weights used to measure torque forces when testing objects in hydrodynamic pipes.

Known tensometric scales containing rigid body and elastic measuring elements and strain gauges placed on the elastic elements. The disadvantage of this balance is that the strain gauges are not exposed to the external environment, and therefore the scope of this type of balance is limited and can be used for hydrodynamic pipes.

As weights for hydrodynamic pipes, tensor-based systems made on the basis of a technical solution can be used, which contain a cylindrical body, elastic measuring elements with strain gauges and a protective casing in the form of a thin-walled flexible shell (bellows), hermetically connected to the body and covering the elastic zone measuring elements. However, the protective casing, made in the form of a bellows, imposes restrictions on the functionality of the balance due to the significant torsional rigidity (which makes measuring torque values difficult), especially when tensile weights are used in hydrodynamic pipes at high hydrostatic pressures, when the bellows wall has to be chosen thick enough. In addition, in case of large differences and separation of various media (liquid on the outside, gas in the bellows cavity), the tightness of the connection between the casing and the housing is required

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are rigid enough to ensure reliable operation of the electrical circuits of the balance.

The purpose of the invention is to expand the functionality of tensile weights by providing torque measurements and increasing reliability under conditions of high hydrostatic pressure.

This goal is achieved in that in scales for hydrodynamic pipes containing elastic measuring elements placed with a cylindrical body, strain gauges and a protective casing made in the form of a thin-walled flexible shell hermetically connected to the housing and covering the area of the elastic measuring elements, the thin-walled flexible shell is made of elastic material and its cavity is filled with a neutral liquid

In FIG. 1 shows scales, general view; in FIG. 2 is a section AA in FIG. 1; in FIG. 3 is a section BB in FIG. 1; in FIG. 4 is a section bb in FIG. 1; in FIG. 5 is a section GG in FIG. 1- FIGS. 6-11 show electrical diagrams of the connection of strain gauges for isolating the respective load components.

Presented tensometric scales contain a cylindrical body, including a piston for mounting model 1 and a holder 2, longitudinal 3-5 and transverse 6 elastic measuring elements with tensor transducers R (. Elastic elements 3 and 4 are made in the form of pairs of beams crosswise located in the transverse section spaced from the axis of the balance and symmetrically located relative to the housing 1. The elastic elements 5 are made in the form of four plates, X-shaped in cross section in the space between the beams 3, 4 and connected along ntsam by means of rigid transverse jumpers 7, 8. Each pair of beams 3 located in one plane is connected to the ends of the piston 1 and with a jumper 7 remote from it, and each pair of beams 4 located in another plane is connected to another jumper 8 and annular intermediate base 9, which is connected through the transverse elastic elements 6 to the mount 10. The transverse elastic elements 6 are made in the form of elastic parallelograms joined by their rigid struts 11, the elastic jumpers 12 of which are uniformly arranged GOVERNMENTAL circumferential radial pairs of parallel communicated with each other (the slits 13) of the holes 14. The racks 11 are respectively connected alternately to the intermediate with a base 9 and a mounting member 10. Placed on elastic elements 3-6 tenzopreobrazovatel RI included in the bridge measuring circuits

in accordance with FIG. 6-11, which are electrically connected with amplification and recording equipment (not shown in the drawings) through sealed connectors 15: zone of elastic measuring elements 3-6

0 is enclosed in a thin-walled shell 16 made of an elastic material (rubber, polyethylene, etc.), tightly connected to the piston 1 and the attachment points 10, and the output wires 17 from electrical circuits 5 are placed in the tubes 18. The cavities of the shells 16 and the tubes 18 are filled with neutral liquid, for example silicone oil. When introducing into the flow of a hydrodynamic pipe of the investigated

0 of the object mounted on the piston 1 of the tensile weights, the hydrodynamic load realized on the object causes the corresponding deformations of the elastic measuring elements of the tensile weights. In particular, elastic bridges 12 experience (mainly) bending, the magnitude of which (due to structural features, locations of strain gauges and features of inclusion in the bridge

0 diagram - FIG. 11) is proportional to the magnitude of the longitudinal force X. A pair of beams 3 is predominantly bent in a vertical plane, while the electrical circuits of FIG. 6, 9, signals are proportional to the vertical force components YI and Y2, which are respectively provided to the front and rear supports (attachment points) of the balance. Similarly, the circuitry of FIG. 7 and 10 formed from strain gauges,

0 located on the beams 4, signals are proportional to the lateral force components Zi and Z2 on the front and rear supports. Additional longitudinal elastic elements 5 are mainly

5 oblique bend, resulting in the electrical circuit of FIG. 8 provides a signal proportional to the torque M. The obtained information on the components X, YI, Y2, Zi, 2z MX allows us to determine all the components of the hydrodynamic load.

Design features of the proposed technical solution provide the following advantages;

- lossless transmission capability (and

5 the ability to accurately measure) torque - i.e. expansion of functionality - due to the low torsional rigidity of the thin-walled elastic shell of the protective casing, the functions of which are changed: not perceiving the pressure drop.

but only the separation of various liquids (therefore, the shell can be selected quite thin);

- providing increased reliability, t, k. the casing does not experience a pressure drop and the liquid environment is not allowed to enter the casing cavity and the strain gauges and electrical circuits of the balance work reliably.

Claims (1)

SUMMARY OF THE INVENTION A balance for hydrodynamic pipes, comprising elastic measuring elements arranged in a cylindrical body with 0 strain transducers and a protective casing, made in the form of a thin-walled flexible shell, hermetically connected to the housing and covering the zone of elastic measuring elements, characterized in that, in order to expand the functionality by providing torque measurement and improving reliability under conditions of increased hydrostatic pressure, a thin-walled flexible shell is made of an elastic material, and its cavity is filled with a neutral liquid. I am AV 16 ft  1 GG / / P1 / it t i. J-I .-- JL - V-1- - -YYY, U  -4 and u u TT  97 B 4-8 K4 ... ™ meter Vb sj No. Л, Мч ,, and 7ffU   3 / y 1 A A / KV C-U (JZ / 7 U, s No. Ј & M5 W: t g wC “th / €“ J at. / OMfc wL75 I am YP) 5 " te2tf.Jft "4 8 # #// C ,, HI I 41+  ,, and 7ff   3 / y   U Fie. 5 liir.G Ј9 eat/  / W aboutFig. 9 FIG. AT her Ј2i / 5 Ј7 1 "city 7 Ј / 5 g / g l R