UA25084U - Method for determining the dynamic tensional stiffness of a shaft - Google Patents

Abstract

The proposed method for determining the dynamic tensional stiffness of a shaft consists in measuring the rotation angles under torque at two differentcross-sections of the shaft by angular position transducers, determining the shaft torque by the corresponding torque transducer or by equation, and determining the tensional stiffness of the shaft by the difference of the rotation angles and the shaft torque.

Description

Description of the invention

The useful model refers to the field of engineering, namely to mechanical processing and can be used in 2 testing technological systems of mechanical processing for torsional stiffness.

A known method of measuring dynamic torsional stiffness, in which the flywheel oscillations are determined simultaneously with the help of a tachogenerator with an empty rotor and wire sensors glued to the rod, which register the elastic moment Mar, |Ryvyn E.I. Dynamika privodov stankov - M.: Mashinostroenie, 1966. - 204 p.: ill. - p.98). 70 Also known, chosen as a prototype, is a method of determining the operating torque and its fluctuations transmitted by the shaft, which consists in converting the angular rotations of the shaft into electrical signals using sensors of the angular position of the shaft and registering these electrical signals during the operation of the shaft under load, while measurement of torques and their oscillations on the machine shaft is done by sensors located in two of its intersections, the pulses from both sensors are phase-synchronized at idle speed, after which the pulses received from the sensors when the shaft is operating under load are measured and compared, the current values of the temporary intervals between adjacent pulses from one of the sensors and between pairs of matched pulses from one and the other sensors, and then determine the instantaneous torque values as a fraction of the distribution of the time shift between the pulses from one and the other sensors by the time shift between the pulses from one of sensors, multiply not by a constant value determined by the formula: С-205/4, where о is 20 modulus of elasticity during torsion; 7 - the number of pulses generated in one revolution of the shaft; | - the distance between the toothed rings on the shaft. (patent of the Russian Federation Mo2002114945 class C 01 1 01/22, 5 01 H 9/00 dated 20.02.2004 Method of diagnosing shafts of rotary machines transmitting torsional loads|.

The disadvantage of this method is the impossibility of accurate measurement of the twist angle when the angular velocity changes during the working and idling cycles, as well as the lack of the possibility of measuring the torque. 29 The common essential features of the known method and the one that is claimed are the conversion of the angular rotations of the shaft into electrical signals using sensors of its angular position located in two of its intersections, the synchronization of pulses from both sensors at idle speed, after which the pulses are measured and compared , received from the sensors during the operation of the shaft under load.

The useful model is based on the task of determining the dynamic torsional stiffness of the technological Z 30 system with maximum accuracy and taking into account dynamic loads that have a variable value rather than a constant one. with

The problem is solved by the fact that the difference in the number of pulses at the end of the output shaft of the machine tool - the spindle is registered by the pulse sensor of the angle of rotation during the exit of the tool from the cutting process, or recorded by the force sensor that determines the corresponding torque, or by the position sensor - with the calculation method of determining the rotating moment

З To the drive end of the output shaft of the machine tool - the spindle for determining the angle of twisting, a pulse sensor of the angle of rotation with a high capacity, which can generate a start pulse, is attached through the coupling. When the moment is accurately determined, a force sensor is installed on the technological system. When determining the moment by the calculation method, sensor "4" is installed on the node of the technological system that makes the feed movement, for registering the position (vibration acceleration, induction, optical, etc.). Sensors for determining the moment, Z 50 vibration acceleration and the angle of rotation are connected to the data processing and registration system . c At the first stage, the cutting process is carried out and, when full contact occurs between the tool and

With" the workpiece, turn off the feed and determine the number of Mo pulses from the start pulse to the last pulse, which is determined by the rotation sensor until the time when the tool leaves contact with the part, and find the force Po (Mo) and the diameter bo, respectively. The output of the tool from the contact is determined by force sensors (when determining the force by calculation, the output of the tool is determined by sensors of vibration acceleration, optical, induction, etc.). 4! At the second stage, the cutting process is performed and when contact occurs between the tool and the workpiece, the number of pulses M is determined; from the start pulse to the last pulse determined by the rotation sensor to the time the tool leaves contact with the part, and find the force P accordingly; (M;) and diameter O.;. o 20 When using the torque sensor, diameter determination is not required.

We determine the difference in pulses of the angle of rotation sensor: s»

AM;- M; - Mo

The twist angle of the end of the spindle is equal to: more АМи оавое с пак де 5 - the discreteness of the impulse sensor of the angle of rotation; s" The twisting angle is measured in degrees. in The moment of the cutting force that caused the twisting angle of the spindle when measured by a dynamometer: mi-v i; so. and in (if the main movement of the tool rotation or processing with a passing cutter is OO; - bo). Dynamic stiffness, is determined by the formula: b5

M, for --- s where |d; coefficient of dynamic torsional stiffness.

Example 1. Diagram of diagnosing torsional rigidity on a lathe, if the cutting force is calculated (see Fig. 1).

On the spindle unit 1 of the lathe 1Ab4, a part 2 with a pre-machined groove 3, necessary for the occurrence of the cutting process during rotation, is installed on one end, and on the other - through the coupling 4 70, a pulse sensor of the angle of rotation 5 of the model KOS 230-9000 of Neideppipe is attached. A slot cutter 7 with a vibration acceleration sensor 8 is installed on the caliper 6. The pulse angle sensor 5 and vibration acceleration sensor 8 are connected to the data processing and registration system 9, which consists of serially connected parts: decoupling amplifier 10, analog-to-digital converter 11 (mod. 1-saga E 14-440), as well as personal computer 12.

Initial data

Y4-1.2 m; 15-52m;

RIET1O000N (calculated value), 0;-207mm,

GI; m;- V --- - 1035Н "m, y

As a result of the tests:

M;-954; Mo-919;

AM M,-Mo-954-919-35;

Spindle end twist angle:

AM; зо ' шф-- 1 3602 ---.36507-14 - air defense package de YuBK-9000;

Dynamic stiffness is determined by the formula: . M, "zo ia---- 739288Н" m/grad.

Oh so

The given example confirms the achievement of the technical result when carrying out the claimed method. at

F iv) ormula invention of the rm. In the school

The method of diagnosing dynamic torsional stiffness, which consists in converting the angular rotations of the shaft into electrical signals with the help of sensors of its angular position located in two of its sections, synchronizing the pulses from both sensors at idle speed, after which the pulses "received from the sensors at operation of the shaft under load, which differs in that the difference in the number of -o s pulses at the end of the output shaft of the machine - the spindle, is registered by the pulse sensor of the angle of rotation during the exit of the tool from the cutting process, recorded by the force sensor, which determines the corresponding torque and . and? moment, or a position sensor - in the calculation method of determining the rotational moment. name) 1 (c) o 50 s" s 60 b5