SU1219930A1 - Method of measuring force and friction coefficient in the area of deformation at rolling - Google Patents

Description

one

The invention relates to the field of pressure treatment, namely, skimming production, and can be used in measuring the vortex and the coefficient of friction in the deformation zone.

The purpose of the invention is to increase the measurement accuracy, simplify the measurement process and expand the range of kinematic-rolling conditions in a four-roll gauge.

FIG. 1 shows the strip deformation process in the four-roll caliber i in FIG. 2 - the same view of the deformation zone from the exit of the strip.

The method is carried out as follows.

0.3

1080

20

0.3

1080

20

Select the workpiece 1 and adjust the caliber 2, formed by horizontal 3 and vertical 4 rollers, so that from one of a pair of rolls, for example, vertical rolls 4, the reduction is 20-30% more than compression from the other pair of rolls ( horizontal). The workpiece 1 is heated to

rolling temperatures (rolling can be carried out without heating) and fed into gauge 2. The drive (not shown) is turned on and after the billet is seized with the rollers, the speed of the decelerating rolls (vertical) is reduced, which is set to a greater reduction, and the speed of the rolls of the other pair is recorded by sensors. (horizontal) and speed of an exit of a strip from rolls and on

their testimony is on trial

Using a roller 10.5 21

10.5 2.1

12.5 2.5 12.5 2.5 17.5 3.5 17.5 3.5

23.5 4.7 23.5 4.7

31

single-zone slip. The strip should come out of the rolls at a lower speed than the speed of the surface of the rolls.

After achieving a single-zone slip on the measuring roll pair (horizontal), the roll moment and rolling force are measured, from which the force and coefficient of friction are calculated using the formulas

T - M.

  R

f

M r-p

where M is the moment on the rolls

R is the roll radius,

P - rolling force. Example. Two batches of round section 0 20 mm are rolled on the Zh-200 universal mill

torsometer 1060 30.5

409

0.386

0.388 0.387

0.390

0.385

1070 34

455

0.425

1280 41

553

0.432

199304

of steel 20. A single batch of blanks rolled in chetfehvapkovom caliber on the proposed salvation. The misalignment of the speeds of one pair of a shaft 5 covas relative to another pair of rolls was set by installing replaceable gears in lower cage gearboxes, and a gradual change in the amount of braking was made by adjusting 10 the amount of reduction on the braking rolls. Another batch of billets rolled in a two-caliber caliber according to a known method.

15 For comparison, one third of a batch of billets was rolled, during the rolling process of which the moments and rolling forces were measured using a roller torsiometer. Measurement data

20 are shown in the table .;

The grip is good, the rolling process is steady.

Capture difficult

0.4285 10.7

Capture does not occur

Rolling is not possible

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1080

20

It can be seen from the table that the value of the friction coefficient, determined by the wx-proposed method, is in good agreement with the data obtained with the help of a roller torsiometer. The magnitude of the coefficient of friction, determined by a known method, turns out to be excessive, which is explained by the increased error of the method caused by the additional friction

12.1 2.4 21.0 4.2

Offered: 10.5 2.1

17.5

3.5

the rolled strip is about the right wiring that needs to be installed so that the strip leaves straight from the cage. The curvature of the strip is made under the action of a single drive and second braking rolls. In addition, there is a hindered capture of the strip by the rollers and an unstable rolling process, which,

in turn, introduces additional errors in measurements. Difficult grip and unstable rolling process are caused by a small reserve of friction forces on one drive roll, which significantly limits the range of measurements, especially at small values of the coefficient of friction.

The proposed method has the following advantages as compared with the known one: it increases measurement accuracy by an average of 10%, simplifies the measurement process, expands the range of measured kinematic conditions of rolling by measuring friction parameters For any degree of steady slip of the strip relative to the rolls.

Claims (1)

METHOD FOR MEASURING FORCE AND FRICTION COEFFICIENT IN THE CENTER OF DEFORMATION DURING ROLLING, including the deformation of the metal in the rolls with the achievement of single-zone sliding relative to the contact surfaces of the rolls and the metal by the mismatch of the speed of the rolls due to braking before slipping, measured. the determination of the forces and moments on the rolls and the determination of the force and friction coefficient, characterized in that, in order to increase the accuracy of the measurement process and simplify it and expand the range of kinematic conditions of rolling in a four-roll caliber, braking a pair of rolls with parallel axes and providing a single-zone slip is carried out by deformation of the metal in a pair of opposite rolls with compression, 20-30% higher than the compression in the first pair of rolls. Figure 1 1219930 ²