FI111984B - Balancing flexible tubular rollers for, e.g. paper machine, by determining direction of mass eccentricity of center of gravity, calculating additional mass and its direction angle, and spraying fluid and additional mass on roller - Google Patents

Abstract

Balancing flexible tubular rollers comprises placing balancing mass inside tubular roller, determining direction of eccentricity of center of gravity of each cross section level mass, calculating additional mass and its angle of direction by each cross section level, spraying fluid and additional mass on roller inner surface to compensate the eccentricity of the location of the center of gravity in cross section levels. Balancing flexible tubular rollers (1) comprises placing balancing mass inside tubular roller, determining the direction of the eccentricity of the center of gravity of each cross section level mass, calculating an additional mass and its angle of direction by each cross section level, and spraying fluid and additional mass on roller inner surface to compensate the eccentricity of the location of the center of gravity in cross section levels. The eccentricity of the center of gravity of the cross section level mass is located in the cross section level of the tubular roller and is from the center. The direction of the eccentricity of the center of gravity of each cross section level mass is determined by measuring the circularity of corresponding cross section level of roller and the deviations from it.

Description

111984

METHOD FOR CONTINUOUS BALANCING LONG FLEXIBLE PIPE ROLLERS

The invention relates to the continuous balancing of long flexible tubular rolls in which a calculated additional mass corresponding to each cross sectional plane is placed inside the tubular roller in each cross sectional plane.

A prior art method is known from Finnish Patent Publication 98404 B1 for continuously balancing a flexible roll 10 or cylinder, in which the measured imbalance is compensated by making new grooves or pockets in the roll or modifying existing grooves or pockets. To balance such a cylinder, the grooves on the surface of the cylinder must be machined separately or must already have grooves. For example, an uncoated paper machine tube roll has a metallic surface and is not allowed to make any grooves. The grooves on the inner surface of such a cylinder, on the other hand, are structural weakening and the grooves also influence the behavior of such a cylinder in the nip contact of the calender. Making grooves on the inner surface of the roll is also a difficult and costly step.

The method of the invention solves the problem of balancing long pipe rolls; 20 problems and significantly improve the quality and accuracy of balancing. The process according to the invention is characterized in that the center of gravity and center of gravity of each desired shear plane mass center is determined by measuring the circumference and deviation of the corresponding cross sectional plane of the tube roll, 25 and inject a fluid and hardening paste into the inner surface of the roll to compensate for the eccentricity of the center of gravity at the desired cross-sectional levels of the tube roll.

Further features or alternatives of the process according to the invention are set forth in the dependent claims.

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An advantage of the method according to the invention is that the inner surface of the tube roll does not need to be machined separately for balancing purposes. In the method, the eccentricity error caused by the shape of the inner surface is taken into account in the form in which the inner surface is. In a preferred embodiment of the invention, the required data to be measured from the tubular roller is obtained from the outside of the tubular roller for easy measurement. By measuring and recording the eccentricity values over the entire roll length at the desired roll cross section frequency, the center of gravity path from end to end of the roll can be determined, which is a prerequisite for continuous compensation for eccentricity. Compensation is effected by means of the injected mass simply on the inner surface of the roll without any grooves or pockets. The method does not cause any disturbance to the roll behavior.

In the following, the invention will be explained in more detail with reference to the accompanying drawing, in which Figure 1 shows a tube roll from the side.

Figure 2 is a sectional view showing the shape defects of the tube roll.

Figure 3 is a cross-sectional view of Figure 2.

Figure 4 shows a measurement of roll rolls and dimensions.

Figure 5 shows a roller tube end with the coordinate system added.

Figure 6 shows a roller tube with an end having an eccentricity and an additional mass.

Fig. 7 shows a roller tube with an injected additional mass tape Fig. 8 shows a roller tube for which additional mass is injected.

Figure 9 shows the eccentricity value of the roll length in x and y coordinate systems.

Figures 1 to 3 show a tubular roller 1 which, regardless of the different manufacturing methods, always contains defects. The tube roll has circular defects and because it has an inner hole, it follows that the wall thickness also varies. These factors mean that the center of gravity of the tubular roller cannot be maintained at the center, i.e. the axis of the roll. Also, the porosity of the roll material or other local differences in the density of the material shifts the weight corresponding to the cross section under consideration: 25 points off the axis line.

:. The method of the invention measures the properties of a tube roll at a desired frequency from selected sequential cross-sections. Fig. 4 shows a measuring situation in which the measuring device 2 · · · · 2 includes a measuring head 6 which indicates the annularity of the peripheral points of the periphery of the tube roll. The measurement thus gives the circumferential emission AR in that cross-section. The sensor is an accurate non-contact distance measuring device known per se.

The measuring sensor 3 measures the wall thickness on an ultrasonic principle, whereby the emulsion required for measurement is fed from the nozzle 4 between the measuring head and the roll surface.

3, 111984

Roller l rotates during measurement and its angular positions and their corresponding measurement values are preferably recorded on a computer connected to the measuring device 2. The measuring device 2 is moved in the direction of the roll to obtain a map of its shape defect and the eccentricity per roll unit selected. The track center of gravity of the roll, which is a continuous curve, is determined and can be used to determine the compensating mass to be applied to the roll surface. The measurement reveals the volume of the roll tube in the cross-section, since the cross-sectional area is always accompanied by the longitudinal distance of the roll, even if it is a differential small distance. Assuming a constant density of such a differential thick ring, the position and direction of its mass center of gravity are determined as described above.

Figure 5 shows the eccentricity e at one point and Figure 6 shows the positioning of the compensation mass 9 on the opposite surface of the eccentricity e.

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Figure 9 shows how the measured calculated eccentricity e can be expressed in the x-coordinate system and in the y-coordinate system as a function of the length L of the tube roll. These allow you to determine ·, · 'at which angular position θ + Π the compensation mass at each position of the roll length L must be positioned ... *. The magnitude of the mass 9 at each point is determined by the magnitude of the eccentricity e.

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Figure 8 shows the injection of a compensation mass 9 into the inner surface of the tube roll 1. The injection device has a shaft 7 and a nozzle 8 at its end. Preferably, the largest 8 is moved axially and the roller 1 is rotated as required by the angular positions. Also, the roller 1 may be stationary and the nozzle rotated and moved axially. Since the amount of pulp varies with the axial direction, the amount thereof, e.g., the thickness of the layer s on the surface can be adjusted at the conveying speed of the nozzle 8 '! *. Another option is to adjust the amount of mass 9 discharged from the nozzle 8 per unit time, e.g. by adjusting the nozzle opening or adjusting the nozzle pressure.

:: Compensation mass is most preferably a curable mass 9, which is a fluid sprayed from the nozzle 8 '* ”· 30. It can cure independently, by heating or by light, such as ultraviolet light. The compensating mass 9 becomes a pulp tape of varying thickness and / or width within the tube roll and extending from the end of the roll to the inside surface of the track determined by the angular positions given by the measurements and calculations.

Claims (8)

111984 A method for continuously balancing long flexible tubular rolls (1), wherein the balancing mass is placed inside the tubular roll (1), characterized in that the center of gravity (e) and the direction (0e) of each desired cutting plane mass center located in the circularity and deviations of the corresponding cross-sectional level of the tubular roll (1), calculating the additional mass required for each of said cross-sectional plane and its angle of incidence (0e + Π) and injecting a fluid ) to compensate for the desired cross-sectional levels of the tube roll. Method according to Claim 1, characterized in that the circularity of the cross-sectional plane and the deviations therefrom are measured by rotating the roll (1) and moving the measuring device (2) in the direction of said roll and recording the measurement results as a function of roll length and rotation angle (0). Method according to Claim 1, characterized in that the measurements are made from outside the roll (1). '· · 20 Method according to claim 1, characterized in that the density information of the roll is measured by measuring the magnetic properties of the roll, the permeability of known rays, or other similar measure of the density and / or porosity of the mass. . and the density data obtained are taken into account calculated by mass volume and its position * · •. / 25 when determining the eccentricity value (e). '..5. The method according to claim 1, characterized in that the additional mass (9) is woven into the inner surface of the roll at a position determined by the continuous rotation angle (0e + Π) and adjusting the amount of mass (9) either by increasing or decreasing the mass or by increasing or decreasing the transport speed of the pulp nozzle (8) relative to the roll. 111984 6. A method according to claim 1, characterized in that the area in the cross-sectional plane and its shape are determined by measuring the wall thickness of the corresponding point and the distance of the peripheral points of the periphery of the corresponding point from the center. Method according to Claim 1, characterized in that the additional mass (9) is injected by axially flipping the mass nozzle (8) and rotating the roller (1) to an angle position corresponding to each axial position. Method according to Claim 1, characterized in that the additional mass (9) is injected by moving the pulp nozzle (8) axially and rotating the various axial positions to respective angular positions with the roll (1) in place. 15