SU684328A1 - Apparatus for dynamic testing of metal-working machine tools - Google Patents

Description

The invention relates to a test and measurement technique and can be used to determine the dynamic characteristics of machine tools. A device for dynamic testing of machines with a hydraulic vibrator 1.1 is known. An integrated frequency spectrum analyzer built into the device improves the accuracy of measurements, but the characteristics are manually taken due to the lack of synchronization of the test signals with the analyzer. The closest to the proposed is a device for dynamic testing of metal cutting machines. It contains a mechanical vibration exciter, excitation force transducers and machine displacement, mixers, the first inputs of which are connected to the excitation force transducer and displacement of the machine, two narrow-band filters whose inputs connected to the outputs of the respective mixtures of telegraphs, the registration unit, connected to the narrow-band filters, and the generator fic th e frequency disadvantage of this device is the inability of the device to different types of mechanical oscillation exciters (hydraulic, and other rotary cam vibrators) that restricts the functionality of the device, limiting classes iccledye vJX machines. The purpose of the invention is to expand the functionality of the device. This is achieved by the fact that the mechanical vibration exciter is rotor-driven, the fixed frequency generator is quadrature, the device is equipped with a quadrature harmonic frequency converter of the rotor rotation of the mechanical vibration exciter and a frequency difference unit, the first two inputs of which are connected to the quadrature outputs of the harmonic frequency converter of the mechanical rotor exciter of mechanical oscillations, the other two inputs to the quadrature outputs of the generator of a fixed frequency, and the output to the second inputs with esiteley. The drawing shows a block diagram (Devices.

The device contains a mechanical oscillation exciter 1, a measuring transducer 2 of the excitation power of the machine 3, a measuring transducer 4 displacements of the machine 3, a quadrature harmonic transducer 5 of the rotor rotation frequency of the exciter 1 mechanical oscillations, mixers b and 7, block 8 of the frequency difference, quadrature generator 9 of a fixed frequency narrowband filters 10 and 11 and block 12 registration.

The device works as follows.

When the rotor of the mechanical exciter 1 is rotated (it can be hydraulic-pulsating, mechanical-cam, ball-shaped, etc.) an exciting system is created at the input of the elastic system of the machine 3.

P

FJ siniut effort that transforms

developed by a transducer force exciter 2

tric signal U 2rUj;, - sin iftt. Moving the elastic system of the machine

nx, s: x, -sin (1 52.1 + f) is converted

measuring transducer 4 movements in the electric signal

and and sin (i "t-t-M) f).

Higher harmonics enrichment of these signals is due to the nonlinearity of the elastic system of the machine; both signals are fed to the corresponding inputs of mixers 6 and 7.

The rotor speed of the mechanical vibration exciter 1 is converted into two sin Sit and cos Sit electrical signals shifted in phase by 90 in the quadrature harmonic converter 5 of the rotation frequency; . these signals are sent to the first two blocks of 8 frequency differences, the signals and cosf, t from the quadrature generator 9 of a fixed frequency are sent to its two other inputs. Block 8 of the frequency difference performs the operation

si p 521 & i p f ot + cos S2t CO & f t "with s (f o-Ya) t

image at its output a signal with a difference frequency (f, -52.), which is fed to the other inputs of mixers 6 and 7. At the outputs of mixers b and. 7, combination components (f -SltiSJ) are formed, of which components with frequency f are allocated in narrowband filters 10 and 11 tuned to them. Thus, all the information about the phase and amplitude of the signals under study is transformed into one fixed frequency and recorded in block 12 registration. When changing in any way the frequency of rotation of the rotor of the exciter 1 of the mechanical oscillation and that caiufciM frequency of excitation -. The proposed device provides for the complete synchronization of the operation of the exciting and measuring parts of the device, i.e. automatic measurement of dynamic characteristics with a ethosection of the main harmonic of the signals of force and displacement.

Claims (2)

1.A.N. der Wolf, Prof Jr.S. de beer. Bin hydraulischer Erreger fiir die dynamische Untersuchung von Verkreugmachinen, Jnd. - Ani. n. 76, 1966. 2. Mintseris BI, Rozman GI, X Arlushas 3, P. Following filters for automated research of M5 machine tools. - Machine tools and tools, 1974, 5.