SU1566237A1 - Method of calibrating torque meter - Google Patents

Abstract

The invention relates to load measuring technique and can be used for the calibration of torque meters. The aim of the invention is to improve the accuracy. A torque unit 2 with a pulley 5 of a given diameter D is connected to the shaft of the torque meter 12 by means of a clutch 11. The drive motor 15, which is part of the meter 12, rotates the meter shaft one turn and records the magnitude of the signal Q _{X of the} sensor 13 force is yuschegos output meter as a function of the angle φ of rotation of the shaft, and then to the pulley 5 via the thread 6 is suspended set 8 cargo 9 given mass M ₀ and again crank shaft meter 12 by one turn and record the value of the signal Q _P sensor 13 forces as a function of the angle of rotation ota shaft, after which the coefficient K is set correspondence between the output signal value meter 12 and the magnitude of the applied torque as a function of the angle φ of rotation of the shaft as a K = ^2. (Q _P -Q _X ) / (M _d -M) ^{. G.} D, where M is the mass of the segment of the filament 6 with length γD, G is the acceleration of free fall. 4 il.

Description

the output signal of the meter 1 and the magnitude of the applied torque as a function of the angle I / rotation of the shaft as

where ha is the mass of the segment of the thread 6 with the length fTD, g is the acceleration of free fall, 4 Il.

The invention relates to load measuring technique and can be used for the calibration of torque meters.

The aim of the invention is to increase accuracy.

FIG. 1 shows a block diagram of an apparatus for implementing the method; in fig. 2 - 4 - the algorithm of the device.

The essence of the proposed method of calibrating a torque meter is that the model torque MQ is applied to the shaft of the meter using a load node including a pulley of a given diameter D, to which a load of a given mass t0 is suspended on a flexible thread, and a correspondence is established between the magnitude of the output signal of the meter and the magnitude of the reference torque applied to it. In this case, before hanging the load, rotate the meter shaft one turn and simultaneously record the output signal O as a function of the angle of rotation of the shaft, then suspend the load and rotate the meter shaft one more turn, registering the value of the output sigal Q p (, gauge as a function of the angle of rotation of the shaft.

The Mismatch coefficient between the magnitude of the output signal of the meter and the magnitude of the applied torque at a given angular position of the rotor is determined from the ratio

- (Qp TQxjf). vT (m0-m) gD where ha is the mass of a length of thread

ffD;

g - free fall acceleration. A device for implementing the proposed method comprises a base 1, a load unit 2 having a shaft 3, bearings 4, pulley 5, thread 6, pallet 7, a set of 8 easily removable certified goods 9 with a specified mass M0, platform U and coupling 11. Est.

The device also contains a torque meter 12, which includes a force sensor 13, a lever 14, a stepping drive motor 15 and bearings 16. In addition, the device includes a measuring and controlling system 1 / containing a microcomputer 18, a control unit 19, a recording device 20, the system bus 21 and the interface block 22.

In this case, the microcomputer 18 has a processor 23, a memory block 24 and a video terminal 25.

The method of calibration of the torque meter is carried out as follows.

The shaft of the driving motor 15 of the torque meter 12 is coupled with the help of the coupling 11 to the shaft 3 of the load unit 2. In the memory block 24, a starting address and a length of the buffer are stored in which the values are stored. Then the numerical values g are entered from the video terminal 25, d, D, corresponding to the specific gravity of the material of the suspension thread 6 used, its diameter and the diameter of the pulley 5. Thereafter, the processor 23 of the microcomputer 18 is transferred to the execution of the startup program of the control unit 19.

The rotation of the shaft of the drive motor 15 at an angle C is performed by applying the 1st control action through the control unit 19 which is operated by the processor 23 of the microcomputer 18.

The drive motor 15 causes the rotational movement through the coupling 11 of the shaft 3 of the load node 2.

The total resistance force 0 creates a moment of resistance Mx relative to the axis of the shaft of the drive motor 15, which is transmitted to its stator and through the lever 14 with the length of the arm 1 acts on the force sensor 13. At the output of the latter, a voltage appears proportional to the resistance force Qx, which, through the analog-to-digital converter unit

515

22 mates is written to the buffer of memory block 24.

To eliminate the error associated with the uneven speed of rotation of the shaft of the drive motor 15 during a step, within one step, n force measurements are taken, over which the average value of the force per step is found (Fig. 2). This value is written to the buffer of the memory block 24, in which upon completion of the complete rotation of the shaft 3 an array of values Qxl is accumulated. In this case, the address of each buffer of the storage unit in which the current value QX is stored (. Corresponds to the current value of the angle of rotation of the drive shaft engine 15.

Upon completion of the first rotation of the shaft 3, the pallet 7 rises to a height equal to and removes from the platform 1P a set of 8 certified weights 9. At the same time, force Or begins to act on force sensor 13 and force output voltage 13, proportional to O, through analog a digital converter of the interface unit 22 is recorded in the corresponding buffer of the memory unit 24.

After the completion of the second revolution of the drive motor shaft 15, the latter is de-energized, while in the memory block 24, in addition to the array O x (the array of values O also accumulates, ordered by the step numbers of the drive engine 15).

Then, using the microcomputer 18, we calculate the mass τ of the length of the filament 6 with the length ffD from the expression / T2 d D-q

. - four

4 and then using a microcomputer 18 for each: 376

up to the angular position of the shaft of the torsional torque 12, the coefficient K is calculated (. corresponding to the magnitude of the output signal of the meter 11 and the magnitude of the applied torque from the expression

v -2IQf: 9- j / l

 t-

 VOn.g.iT

ten

Claims (1)

Invention Formula The method of calibration of the torque meter, consisting in that a load node with a pulley of a given diameter D is attached to the gauge, to which a load of a given mass m is suspended on a flexible thread and set accordingly between the magnitude of the output signal of the meter and the magnitude of the torque acting on it, characterized in that, in order to improve the accuracy, before suspending of the load, rotate the shaft of the meter by one turn, register the magnitude of the output signal Ox meter and functions of the angle i / rotation of the shaft, then hang the load and again rotate the shaft of the meter one turn and record the output signal of the Oru measured by the angle as a function of the angle (/ rotation shaft, then set the coefficient K (. correspondence between the magnitude of the output signal of the meter and the magnitude of the applied torque as a function of the shaft angle J, determined by the formula „JL (Gfir9-) , () R V where m is the mass of the segment of the thread length D; g - free fall acceleration. f Start Set the starting address of the Qx buffer Keep the values of q., Ct, D Turn on breaker (stepper) electric motor Apply 1st control action to the drive motor Perform N measurements at 1st position, rotor relative to stator Remember results x ,,,,. in the intermediate buffer of the memory unit P calculate bdg vd  L in / Write Q to Q buffer Increment by J address d ufer Q P one 1 "v FIG. 2 Lidodnoy lecturer kept one turn ,Yes Install the load Xx Fi & W Unplug the receipt motor Calculate / 77 - Calculate coefficient values / G g (t o-t) -a one Build a buffer of K values Determine the values of L / L: the recording device and on the screen of dideoterminal WITH ga one the end J