SU1471090A1 - Magnetoelastic stress transducer - Google Patents

Abstract

The invention relates to force-measuring technology and allows the size and weight of the sensor to be reduced while increasing the upper limit of measurement. The external closed magnetic core 4 is connected by evenly arranged circumferential magnetic needles 2 with hub 1. On the external magnetic circuit in the areas between the spokes and in each needle there are slots 3 and 5 dividing these areas into two rods, one of which is covered by magnetizing 6 and 7 and the other - measuring 9 windings. When a compressive force is applied to the end of the hub, mechanical compressive stresses arise in the rods of the spokes, and tensile stresses appear in the rods of the external magnetic core between adjacent spokes. In this case, the magnetic resistances on the magnetic flux paths change, violating the equality of the emf. 4 il.

Description

(21) 3780541/24-JO

(22) 08/14/84

(46) 04/07/89. Bul № 13

(71) Kiev Institute of Automation. XXU Congress of the CPSU

(72) E.V., GolovanJ Yu.I.Ivanov, - S.P.Kartsev and N.S. Ruban

(53) 531.781 (088.8)

(56) USSR Copyright Certificate No. 247567, cl. G 01 L 1/12, 1967.

USSR Author's Certificate No. 535476, cl. G 01 L 9/16, 1974.

(54) MAGNETIC ELASTIC SENSOR OF FORCES

(57) The invention relates to a measuring instrument and allows. reduce the size and weight of the sensor by increasing the upper limit of measurement. The external closed magnetic core 4 is connected by uniformly arranged circumferential magnetic conductors 2 and hub 1. On the external magnetic core, slots 3 and 5 are made in the sections between the spokes of each spoke, which divide these sections into two rods, one of which is covered by magnetizing 6 and 7, and the other - measuring 9 windings. When a compressive force is applied to the end of the hub, mechanical compressive stresses arise in the rods of the spokes, and tensile stresses appear in the rods of the external magnetic conductor between adjacent spokes. In this case, the magnetic resistances on the magnetic flux paths change, violating the equality of the emf. 4 il.

and s

(L

F / 7T

FRZ

four

WITH

about

15

The invention relates to load engineering and can be used in automatic process control systems for measuring forces, for example, during rolling.

The purpose of the invention is to reduce the size and weight by reducing the magnitude of the mechanical stresses in the measuring rods.

Figure 1 shows the magnetoelastic force sensor, a general view; figure 2 - section aa in figure 1; Fig. 3 shows one of the possible schemes for the electrical connection of the windings; 4 is a static sensor characteristic.

Magnetoelastic force sensor. (Fig. 2 and includes a hub 1, to which a measured force is applied, magnetic needles 2 with slots 3 and an external magnetic circuit 4 with slits 5 in the areas between adjacent spokes, as well as annealing windings 6, 7 and measuring 0.9 .

The magnetizing windings (Fig.2), located on the corresponding rods of the spokes (Wrp, Wnp, Wnrz,) are connected in series to the opposite side, also connected between each other magnetize windings located on the rods external magnetic conductor (W., W ,,,, WHC3..W «o4). The magnetizing winding group, located on the spokes, is connected in series according to the magnetizing winding group on the external magnetic circuit.

The measuring windings, located on the needles (,, W.p., W.p, Wyp), are interconnected in series and counter, the measuring windings located on the external magnetic field are also joined together.

20

25

thirty

water (W

I01 Could

W

ioz

and

U04

). The group of measuring windings, placed on the spokes, is connected in series to the counter with a group of measuring windings placed on the external piping line. A measuring device is connected to the output of the measuring circuit,

Magnetoelastic force transducer: working in the following way.

When the magnetization circuit is connected to the alternating current source of the magnetic circuit, magnetic fluxes occur along the spokes.

55

35

15

-

20

25

thirty

F

F,

 12 )

And magnetic

F,

2

Fs

RZG Gr4 (by the number of spokes), FLOWS Fo ,, Fo ,, F „, F

passing through the outer magneto-; water and closing around the corresponding gap.

The main part of the magnetic flux FR passes in the radial direction, and the main part of the flows in the circumferential direction. The emf induced in the measuring windings, in the absence of forces, is equal. The resultant EMF E with the opposite switching on of the groups of measuring windings on the spokes and on the external magnetic conductor is zero.

When a compressive force is applied to the end of the hub, mechanical compressive stresses arise in the rods of the spokes, and tensile stresses appear in the rods of the external magnetic conduit between the adjacent spokes. In this case, the magnetic resistances on the paths of the Magnetic fluxes Fr and F change. The magnetic resistances of the radial sections of the spokes (in the paths of the currents are exaggerated, and the circumferential bridges of the external magnetic circuit (in the paths of the fluxes F ,,) decrease induced in the measuring windings on the spokes (Ep) and on the external magnetic core (E), as a result of which: at the output of the sensor, the emf

35 EU equals

E „E p -.

The static characteristic of the proposed sensor has a rattle character (FIG. 4).

Formula and

acquisitions

40 45

P

five

A magnetoelastic force sensor containing an external closed magnetic circuit, magnetizing and measuring windings, characterized in that, in order to reduce overall dimensions and mass, with an increase in the upper limit of measurement, a hub is inserted into it, connected by evenly arranged circumferentially magnetic-conducting needles to an external magnetic circuit, while the spokes and the outer magnetic circuit are located in the same plane, equidistant from the ends of the hub, and on the outer magnetic circuit on the areas between the spokes and in each spoke-field There are no slots separating these areas.

fJHp1

II U / IR

nr2

13 And W - // 72

vp

 II irZ B II

U / No1 II

Ww2 ww3

st no:

 not

FIG. 2

Wi /

-and

V / uo

Claims (1)

Claim A magnetoelastic force sensor containing an external closed magnetic circuit, magnetizing and measuring windings, characterized in that, in order to reduce dimensions and mass, while increasing the upper limit of measurement, a hub is connected to it, connected by magnetically conducting spokes evenly spaced around the circumference with the external magnetic circuit, this spokes and the outer magnetic core disposed in the same plane, equidistant from the ends of hub, and the outer magnetic core portions ¹ on and between the spokes at each spoke is formed the gap separating these cores uchast1471090 ki two rod vayuschey, another - from the measuring obodin kotorge covered magnetization, + z. skeins. Aa U / NR1 II fr Wup1 P_3 $ Wup2 G Whoz Eunoz Vjho ^ II II II Ml <tWUp3 L— YIR \ Wuo1 Ate \ Wua2 ΕΖ ShioZ $ XWuo ^ Fig.Z