JPS60232858A - Automatic grinding of rolling roll - Google Patents

Abstract

PURPOSE:To remove flaw of roll completely by grinding while anticipating the type, the position, the depth, etc. on the basis of a roll surface flaw signal to be produced through a vortex or a supersonic probe arranged on the surface of a rotary roll. CONSTITUTION:A grinding wheel to be driven through a motor will reciprocate longitudinally and vertically against a reciprocal table. A grinding wheel cover 5 is fixed with a flaw detecting mechanism to contact the detecting end 6 against the surface 1s of roll 1 and to stabilize the contact of probe through a contact roll 7 and a spring 8. The surface of roll 1 is splitted and addressed through roll rotation pulses and grinding wheel traversing pulses while the grinding amount is obtained from the diameter and the composition of roll 1, current of grinding wheel drive motor and the traversing speed thereafter the depth of flaw is anticipated from a signal characteristic curve showing the relation between the grinding amount of roll and the flaw of roll while considering the magnitude of specified level, occurring position and the type of flaw on the surface of roll to control the grinding wheel drive current thus to perform grinding.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a Ryodoken Filj method for rolling rolls.

(Prior Art) As is well known, rolling rolls are used to roll metal plates such as hot or cold upper layer E&A plates and aluminum plates.

Normal rolling involves rolling from a wide range of materials to a narrow one, but there is a limited area through which the edge of the board passes, and in that area, the surface of the roll is rough due to stress concentration during rolling. However, cracks and changes in the roll material occur. If you continue rolling without knowing that there are cracks, this can lead to serious accidents such as breakage of the roll. Therefore, in general, after rolling a certain tonnage depending on the purpose of the material to be rolled, the material, the width schedule of the rolled material, etc., the material is removed and the surface of the roll is ground and polished.

If the surface of the roll is presumed to be free from scratches, grinding of the surface of the roll can be done by grinding the motor that drives the grindstone, as shown in JP-A-43-22948 and JP-A-44-8309. By monitoring and controlling the current value,
Roll grinding begins with grinding the roll edge, then heavy grinding over the entire length of the roll, and finally a polishing process with almost no grinding.The roll is automatically ground and polished to the desired amount of roll crown. be able to.

However, for rolls that require attention if they have been squeezed or stuck during rolling or have had past defects, they should be ground or polished after conducting penetrant testing or magnetic particle testing to estimate the size of the defects. conduct.

Although we take great care in grinding, there is no guarantee that harmful flaws have been completely removed. Naturally, there are cases in which roll flaws occur in a roll that has been previously free of flaws, but the roll flaws are not completely removed by normal grinding.

(Objective of the Invention) The present invention fundamentally improves the above-mentioned drawbacks of automatic grinding, and performs automatic grinding to completely remove roll flaws.

(Structure and operation of the invention) The gist of the present invention is to arrange a four-rotation grindstone having a feeding device that can move horizontally parallel to the axis of the rolling roll and back and forth perpendicularly to the axis while rotating the rolling roll. In the grinding method, an eddy current flaw detection glove or an ultrasonic flaw detection glove is placed on the roll surface, and based on the roll surface flaw signal obtained by this, the type, position, flaw depth, etc. of the roll surface flaw can be estimated. The present invention also provides a method for automatically grinding a roll, characterized in that the roll is automatically ground until there are no harmful flaws on the roll.

The method of the present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a plan view showing a state in which a roll to be ground 1 is placed on a grinding machine, and a grinding wheel 2 is driven by a motor 3 and a carriage 4
It reciprocates in the longitudinal direction and in the perpendicular direction. FIG. 2 shows an embodiment of the present invention, and is a surface measurement diagram showing a state in which a roll flaw detection mechanism is attached to a grinding wheel cover 5.
is in contact with the roll surface 18. The contact of the probe is multi-stabilized by Co/Cuctorol 7 and Gune 8.

The detection end arm 9 is approximately 18
It is rotated by 0° and retracted, so that there is no problem in setting the roll l on the grinding table and raising the ib. At the detection end 6, for example, a Japanese magazine "Nondestructive Inspection" vol. 23. A9 P
A vortex globe and/or an ultrasonic surface wave probe can be used, as seen in the report of P494 and JP-A-51-151590. The vortex globe is suitable for use in casting and forging rolls, and the surface wave probe is suitable for use mainly in cases where crystal grains are relatively small, such as forging rolls. The signal flow until a roll flaw signal is obtained using an eddy current probe is roll flaw → eddy current Zorope → high frequency bridge unbalance → phase detection → filter → flaw discrimination → roll flaw signal.

If a surface wave probe is still used, the process is roll flaw → surface wave glove → reception of reflected waves from roll flaw → flaw discrimination → roll signal.

In addition to the roll flaw signals obtained by the above-mentioned eddy current and/or surface wave flaw detection, this device also uses grinding machine data such as the current of the grinding wheel drive motor, roll rotation pulse, grinding wheel traverse pulse, and grinding wheel diameter, and the material of the grinding roll. and roll grinding information such as the roll crown pattern are sent to a dedicated microcomputer to estimate the type and depth of the flaw, set an optimal roll grinding schedule, and control it.

Next, the automatic grinding process will be explained in more detail.

The roll flaw detection edge moves sideways from time to time, and the roll also rotates, so no matter which flaw is detected using an eddy current globe or a surface wave probe, the flaws may not be the same depending on the relative positional relationship between the flaw and the probe and the shape of the flaw. Even if there is a defect, its indicated value fluctuates greatly. Furthermore, as shown in FIG. 3, the degree of harm is different depending on whether a flaw 12a occurs in the part 11 where the end of the plate touches and a flaw 12b occurs in other parts.

Therefore, the roll surface is divided into addresses as shown in FIG. 3 based on the roll rotation pulse and the grindstone traverse pulse, and the position of the flow generation is determined. 13 is one area divided into addresses.

On the other hand, the amount of grinding can be determined empirically from the diameter and material of the roll, the current of the grindstone drive motor, and the traverse speed.
9v+fG: Grinding amount Dg: Grinding wheel diameter ■ = Grinding wheel drive motor current Dr: Roll diameter Ng: Grinding wheel rotation speed V: Traverse speed a, b...f: Constant depending on roll material and grinding wheel drive motor current, used in experiments Determine using the method of least squares.

Demeru.

Next, among the flaws 12 on the roll surface 18, the three most harmful flaws, judged from the size of the indicated value and the location and form of occurrence, are subjected to roll grinding as shown in Fig. 4. A quantity-roll flaw signal characteristic curve 14 is created to estimate the flaw depth.

Based on the highly reliable estimated flaw depth obtained in this way,
The optimum grinding amount is obtained by taking into account the harmful flaw limit level 15a of the part where the sheet edge touches and the harmful flaw limit level 15b of the other parts, which are determined based on past accumulated data in consideration of the roll flaw occurrence position. Then, by controlling the grinding wheel drive current, etc.
As shown in FIG. 4, as the flaw signal becomes weaker, the amount of grinding is gradually reduced as indicated by 16 in the figure.

Naturally, the estimated value of the flaw depth is corrected each time the detection end scans over the flaw to avoid excessive grinding. Furthermore, even if the most harmful flaw moves to another location, the grinding schedule etc. are automatically changed accordingly.

The present invention is equipped with a roll surface flaw detector and performs grinding while estimating the flaw depth, but a leakage flux type probe may also be installed at the detection end.

(Effects of the Invention) As explained above, according to the present invention, roll surface flaws are detected in real time, and the necessary grinding amount for the flaws, that is, the flaw depth, is estimated while grinding and polishing is performed using an optimal grinding schedule. As a result, the rolls ground by this grinder do not have any flaws that would be harmful to rolling, there is no need for conventional penetrant testing, and roll grinding does not require any manpower.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an example of the apparatus used in the method of the present invention, Fig. 2 is a surface measurement of an example of the apparatus used in the method of the present invention, and Fig. 3 is a roll surface on which roll defects are identified by the method of the embodiment of the present invention. Figure 4 is a diagram showing how the roll flaw depth is sequentially calculated and estimated by the method of the embodiment of the present invention, and Figure 5 is a cross-sectional view of the roll flaws ground and removed by the method of the embodiment of the present invention. be. 1: Roll to be ground 2: Grinding wheel 3; Motor 4: Reciprocating table 5: Grinding wheel cover 6 = Sensing end 7: Contact roll 8: Spring 9: Sensing end arm 10: Torque cylinder 11
: Area in contact with board end 12: Flaw 13: Address-divided area 14: Roll flaw signal characteristic curve 15: Harmful flaw limit level. Figure 1 Figure 2

Claims (1)

[Claims] In a method of grinding by arranging a rotating grindstone having a feeder that can move horizontally parallel to the axis of the roll and back and forth perpendicularly to the axis while rotating the rolling roll, an eddy current flaw detection glove or an ultrasonic flaw detection method is used. A probe is placed on the roll surface, and based on the roll surface flaw signal obtained, the type, position, and depth of the roll surface flaw are estimated.
Automatically polishes the rolling roll until there are no harmful flaws.
1j method for automatic polishing of a rolling roll.