SU1364919A1 - Torque instrument transducer - Google Patents

Abstract

The invention can be used as an autonomous measuring device or as part of an information measuring system as a torque converter. The purpose of the invention is to improve accuracy. In the housing 9, a fixed part of the current collector is installed, made in the form of a ferrite ring 1 O with the primary winding 11, which is connected to the output of the write amplifier 15 and the input of the read amplifier 16. The recorder circuitry includes a pulse generator 20, a delay element 17, a one-shot 18, circuits 13 and 14, and a trigger 19. The magnitude of the torque on shaft 1 is determined by measuring the change in the time interval with respect to the value taken as the origin. The purpose of the invention is achieved due to the linearity of the function of converting a twist angle to a time interval. 3 il. with i (L

Description

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The invention relates to a technique for measuring mechanical quantities, in particular torque, and can be used as a stand-alone measuring device or as part of an information-measuring system as a torque converter on rotary and stationary shafts,

The aim of the invention is to increase the accuracy.

FIG. 1 shows a converter block diagram; in fig. 2 - mutual arrangement of the acoustic duct and the magnetic head under the conditions of action (dotted line) and the absence of torque; in fig. 3 - signal plots explaining the operation of the converter.

The torque converter contains a shaft 1 with an elastic section 2, to one end of which a disk 3 is attached, on which an electromagnet 1P converter 4 is mounted, and to the other is a ferromagnetic ring 5 with a radial section 6 (Fig. 2), mounted concentric but the shaft axis 1 and inductively coupled to the electromagnetic converter A, the transformer current collector 7, including the stator winding 8 on the ferrite ring 9, and mounted on the base 10, and the rotor winding 11 connected to the electromagnetic transformer The recipient and made on the ferrite ring 12 mounted on the shaft 1, two circuits And 13 and 1A, two amplifiers 15 and 16, serially connected delay element 17 and one-shot 18, trigger 19 and pulse generator 20, the output of which is connected to the input of delay element 17 and through the amplifier 15 to the stator winding 8 of the transformer current collector 7 and the input of the amplifier 16, the output of which is connected to the first inputs of circuits I 13 and 14, the outputs of which are connected to the corresponding inputs of trigger 19, and the second inputs of circuits And 13 and 14 are connected respectively to directly and and Outputs of the one-shot 18.

In this case, the electromagnetic transducer 4 is made in the form of a toroidal coil with a working gap deployed to the ferromagnetic ring 5 with the provision of an air gap

g 0

5 o

five

0

five

between the ferromagnetic ring 5 and the electromagnetic transducer 4.

The torque converter works as follows.

Pulse generator 20 (Fig. 1) generates a start pulse V (Fig. 3), which through amplifier 15 is fed to the stator winding 8 of the transformer current collector 7, from the rotor winding 11 of which the signal is fed to the electromagnetic converter 4. In the area of the ferromagnetic ring 5 , covered by the magnetic field of the transducer 4, due to the appearance of magnetostriction, an acoustic pulse is excited, which propagates through the ferromagnetic ring 5 to both sides of the excitation site.

After reflection from the end surfaces in radial section 6, the acoustic pulses return to the transducer 4 and, due to the inverse magnetostrictive effect, induce a pulse Vj in it. In order to increase the efficiency of direct and inverse electroacoustic transformations, near the region of the ferromagnetic ring 5, inductively coupled to the converter 4, there is a biasing element, which can be made, for example, in the form of a permanent magnet fixed on the disk 3.

After the trigger pulse, perceived by the amplifier 16 as an interference Vja, the pulse VjS reflected from the end of the ferromagnetic ring 5 closest to the transducer 4 in the radial section is read first. The time delay r, pulse Vj relative to pulse V- (determined from the expression

., 5- i,

(one)

where R is the radius of the ferromagnetic ring 5; C - the speed of sound in the material

rings 5;

(- the position angle of the nearest end in radial section 6 relative to the electromagnetic transducer 4. Similarly, the delay tj of the pulse Vj is determined - i.e. the reflected pulse from the far end

/ G - 2R p ---

(2)

where if2 is the position angle of the far end in radial section 6 relative to the electromagnetic transducer. The difference in the delay time of the pulses Vji and Vzi, in the absence of torque, corresponds to the time interval:

t, T5-t, 2R (

(3)

which is constant for each specific configuration of the initial mutual arrangement of the transducer 4 relative to the radial discharge 6 of the ferromagnetic ring 5.

When a torque is applied to the shaft 1 yviitp, the elastic section 2 of shaft 1 is twisted at an angle of 4 I proportional to 1). When this occurs, the angular displacement C of section 6 of the ferromagnetic ring 5 relative to the transducer 4 (Fig. 2) occurs, and the difference in the delay times of the pulses Hg and corresponds to the time interval Tf-:

2R,

P (, .ch, -2. And

(four)

Thus, the increment of the delay time difference

.f, / g f 4Rf

and 4

(five)

proportional to the twisting angle of the elastic section 2 of shaft 1, which is equivalent.

I G

(6)

where q is a constant torque measuring transducer taking into account the radius of the ferromagnetic ring 5, the speed of sound propagation in the material of the ferromagnetic ring 5 and the elastic properties of the material of the elastic section 2 of the shaft 1.

Thus, the value of the magnitude / HER is determined by measuring the change in the difference in the delay times of the pulses Vj and Ue, i.e.

For this, the pulses 2f (Fig. 3) pass through the transformer current collector 7, are amplified by the amplifier 16 (Vj in Fig. 3) and are fed to the first

ten

- 20 5 30

35

40

45 wat 50

94

the inputs of circuits 13 and 14, which, in conjunction with the one-shot 18, carry out temporal selection of pulses. In this case, the pulses fall within the time interval defined by the diagram Vj (Fig. 3) of the direct output of the one-oscillator 18, the beginning of which is indicated by T (Fig. 3) and is determined by the duration of the interference from the trigger pulse Vja, and the end of T is equidistant from the time signal the position of the read pulses UZ,} and Vzg. From the output of the element And 13 pulses Vj- arrive at a single input of the trigger 19 and set it to a single position corresponding to the beginning of the time interval C at the output of the converter (Vg).

The pulses f,, come after the moment TO and through the element AND 14 (V), arrive at the zero input of the trigger 19 and set it to the zero position corresponding to the end of the time interval fy, (Vj). At the same time, the pulses of the initial part Vj caused by the interference V2q from the start pulse, received during the action (n delay element 17), set trigger 19 to the initial zero position and at the beginning of each start cycle correct possible random failures of previous cycles in the torque converter operation .

Taking into account the length of the so-called dead zone T, due to the action of the interference of the trigger pulse in the read channel, the pulse duration at the direct output of the one-oscillator 18 is chosen equal to

1c T (, - T,

where Ta is the range of the acoustic impulse of the entire length of the ferromagnetic ring 5:

T, (. +,).

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Claims (1)

Invention Formula A torque converter, a shaft with an elastic section, an electromagnetic converter attached to one of the ends of the elastic shaft section, and a transformer current collector including a stator winding mounted on the base and a rotor winding mounted on the shaft and Fie.2 f (/ - y tf t