SU1576854A1 - Method of determining machinability of materials in flat grinding - Google Patents

Abstract

The invention relates to the study of materials when machining with an abrasive tool, in particular to assessing the workability of both the material itself and various abrasive materials during flat grinding. The purpose of the invention is to improve accuracy. For this, the reference and test materials are processed with a single instrument. The amplitude of the vibroacoustic emission signal is measured during forward and reverse travel for the specified materials. Find the difference between the averaged amplitudes of the vibroacoustic signal during the forward and reverse run for the reference and test materials. The difference between the calculated values is determined by which the machinability of the test material is judged. 1 il.

Description

The invention relates to the study of materials in the processing of an abrasive tool, in particular, it is used to assess the workability of both the material itself and various abrasive materials.

The purpose of the invention is to improve accuracy.

The drawing shows a diagram of the device for illustrating the proposed method.

The method is carried out as follows.

The workpiece 1 is mounted on a magnetic table surface grinding machine, on the workpiece install the sensor 2, which perceives the vibration signals

roacoustic emissions arising in the cutting zone. The sensor is connected to the switching unit 3. The latter is controlled by a sensor 4 for forward and reverse strokes of the table of the grinding machine. The outputs of the switching unit 3 are connected to the unit 5, which stores the amplitude of the vibroacoustic emission signal during forward running and the unit

6 memorization of vibroacoustic emission during the course of the table. The outputs of the memory blocks are connected to the circuit.

7, where the difference between the values of the signals of blocks 5 and 6 is determined. The output of the comparison block is connected to analysis block 8, which is a converter of the difference of two signals into a decimal code.

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Since the machinability is largely determined by the AIDS system (machine, tool, tool, part), before using the method, it is necessary to calibrate the device that implements the proposed method.

To do this, on a machine that determines workability, for example, on a 1E711B-1 surface grinder, a workpiece is made of a reference material for which machining modes from reference books are recommended. A grinding wheel with predetermined physicomechanical properties is installed on the machine, for which there are already recommendations on operating modes for known materials. The grinding wheel is edited in order to avoid working with a wheel that has wear. Further in the treatment area, i.e. on the sample, install the sensor vibroacoustic emission. Then, the rotation speed of the Ucr circle, the longitudinal feed of Snp and the cutting depth t (for example, for a hard alloy T 15K6 and a diamond wheel with AGO Ukryi28 m / s grains; Snpu2 m / min; t ft “0.008 mm / two-way) are set .

From the expression V "n X Spp С Q, the specific metal removal is determined. The cutting is done and the difference between the amplitudes of the vibro-acoustic emission signals is determined during forward and reverse moves of the table. The obtained Diet value is taken as 100% workability, which corresponds to the specific metal removal Q for modes V, Spp, t of the material taken as the standard.

When examining a new material for machinability, the same grinding wheel is taken, the wheel is edited, the same processing modes as for the standard are set, and the cutting is performed. UU is determined for the material under study, then compared with Diet, while, if UU is Di, the workability is higher than that of the standard, and it is possible to increase the feed rate or

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cutting depth. An increase in feed and cutting depth leads to an increase in the specific metal, however, De decreases, as more stringent modes lead to more intensive wear of the grinding wheel grains, and during the reverse course of the table, the amplitude of the vibro-acoustic emission signal increases.

By changing the parameters of t, one obtains that UU Diet, while Qg is different from Q of the material under study.

When the reduction of the parameters S p. And t is carried out until Di Die. In this case, Q3 is greater than Q of the material under study, which indicates poor machinability of the material under study. Variation of parameters is necessary only if the task is to assign technological parameters for the material under investigation, at which the wear rate of the grinding wheel would be commensurate with the wear rate of the grinding wheel when processing the reference material (this is necessary in order to specify the time in the flow chart which is necessary to correct the circle, and exclude the possibility of marriage).

Claims (1)

Invention Formula A method for determining the workability of materials during flat grinding, which consists in that the reference and test materials are processed with a single instrument and the amplitudes of the vibroacoustic emission signal are measured during a forward run, characterized in that, in order to improve the accuracy, the amplitudes of the vibroacoustic emission signal are measured during the return stroke for both materials, the difference between the averaged amplitudes of the vibroacoustic signal in the forward and reverse runs for the reference and test material is determined als and the ratio of the values obtained was determined machinability test material.