JPS6052904B2 - How to grind steel plate - Google Patents

Description

Detailed Description of the Invention The present invention is applicable to steel plate grinding, which is applied to scale removal of steel plates, surface grinding of stainless steel plates, or grinding of a single-sided plating layer on a double-sided plated steel plate in order to produce a single-sided plated steel plate from a double-sided plated steel plate. It is about the method.

Nowadays, steel plates for automobiles and electrical products can be used with either a zinc-coated surface, which requires corrosion resistance, or a non-plated surface, where weldability or paintability is more important than corrosion resistance.

There is an increasing demand for so-called single-sided plated steel sheets. By the way, the manufacturing methods for single-sided plated steel sheets are roughly divided into methods in which selective plating is applied only to one side of the steel sheet, and methods in which plating is applied to both sides of the steel sheet and then the plating on one side is removed. Since the former method requires a large number of man-hours for the pretreatment process, the latter method, which does not require any special pretreatment, is often adopted. By the way, even when adopting the latter method mentioned above, the plating layer can be specifically divided into two methods: chemically dissolving and removing it and mechanically polishing and removing it. As with the former method, the method of dissolving and removing requires a pretreatment process and has low manufacturing efficiency, so mechanical grinding methods, which do not require a pretreatment process and are highly efficient, are often used. has been done. In the past, the method of mechanically removing the plating layer on one side of a double-sided plated steel plate was carried out as shown in FIG. In FIG. 4, S indicates a double-sided plated steel plate, and after this double-sided plated steel plate S is pulled out from an uncoiler (not shown),
The first stand is passed between the grinding roll 41 and the backup roll 42 and is applied to the plating layer on one side.
The next grinding is performed, and then the remaining plating layer is passed between the grinding roll 51 and the backup roll 52 in the second stand to perform the second grinding to produce the single-sided plated steel plate 5, and then the plated steel plate 5 is transferred to the It is transported in the direction indicated by the arrow and wound up by a coiler (not shown). However, this method requires a large space for installing stands for the grinding rolls 41 and 51, and has the disadvantage of increasing equipment cost. In order to solve this problem, it is natural to reduce the number of stands to one, but if the number of stands is one, for example, in the case of a single-sided plated steel sheet for the exterior of an automobile, the amount of zinc deposited on the plated surface will increase. requires about 4591d, and the amount of residual lead on the non-plated surface is 50%.
Since it is necessary to suppress the zinc coating amount to less than m91a, if a double-sided plated steel sheet is obtained by hot-dip galvanizing, even if the amount of zinc deposited on the non-plated side can be slightly reduced, the amount of zinc deposited on the non-plated side is The grinding allowance is relatively large, and in order to achieve this with a single grinding roll, it is necessary to increase the rotation speed of the grinding roll and also to increase the contact pressure of the grinding roll against the grinding surface. If this is carried out, the grinding roll will wear quickly, its life will be extremely short, and the cost of the roll will increase.In addition, it will be necessary to reduce the transport speed of the double-sided plated steel sheet S itself, which will result in a decrease in manufacturing efficiency. , the current situation is that two or more stands have to be installed. The present invention has been made in view of the above circumstances, and its purpose is to allow a single stand to grind a steel plate multiple times in the same way as when multiple stands are used, and to facilitate installation of the equipment. To provide a method for grinding a steel plate which requires only a small space and can greatly improve grinding efficiency.

The method of grinding a steel plate according to the present invention is a method of grinding using one or more rotationally driven grinding rolls, in which a bus line of the steel plate is set in contact with the peripheral surface of a single grinding roll at two places, It is characterized in that the grinding surface of the steel plate is brought into sliding contact with the peripheral surface of a single grinding roll twice for grinding.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A case in which the present invention is applied to a continuous production line for single-sided plated steel sheets will be specifically described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the applied state of the method for grinding a steel plate according to the present invention (hereinafter referred to as the method of the present invention), and FIG. 2 is a schematic diagram showing an apparatus for carrying out the method of the present invention and its control system. , S in the figure indicates a double-sided plated steel plate. Double-sided plated steel plate S is its material. is pulled out from an uncoiler (not shown). and passed through the reduction furnace 1 to reduce the surface.
The molten zinc is introduced into the molten zinc tank 2 without contacting with the atmosphere, molten zinc is deposited on both surfaces through the molten zinc tank 2, and the amount of zinc deposited is controlled in the process of being pulled vertically upward from the molten zinc tank 2. Then, it is cooled and transferred to chromate treatment unit 3.
After being subjected to chromate treatment, it is transported toward the coiler in the direction of the white arrow, but during this process, the plating layer on one side is removed by polishing using the method of the present invention, and the single-sided plated steel sheet S
1 and transferred to the coiler. The apparatus for carrying out the method of the present invention includes a grinding roll 4 and a backup roll 5u.
, 5d, pinch rolls 6, 7, tension roll 8, and a plurality of nozzles 9 for water supply are its main components.

The grinding roll 4 is made of a synthetic resin with appropriate elasticity containing abrasive grains, and has a double-sided plated steel plate S and an axial length that is equal to or slightly longer than the width,
It is formed into a cylindrical L body having a predetermined diameter, and is driven to rotate in the direction of the arrow so as to come into sliding contact with one plated surface of the double-sided plated steel plate S by a motor (not shown). Backup rolls 5u and 5d are grinding rolls 4
The plated surface a of the double-sided plated steel plate S to be ground is brought into surface contact with the circumferential surface of the grinding roll 4 with an appropriate contact pressure. The upper position of the grinding roll 4 is adjusted by the roll position setting device. It is arranged so that it can be moved downward.
The pinch roll 6 is placed at the introduction position of the double-sided plated steel sheet S relative to the first grinding position A by the grinding roll 4 and the backup roll 5u, and the pinch roll 7 is also placed at the second grinding position by the grinding roll 4 and the backup roll 5d. The single-sided plated layer derived from position B is disposed in the passage area of the ground single-sided plated steel plate S1 at an equal distance from and on the same side of the grinding roll 4, and on the other hand, a tension roll 8 is provided.
has a slightly smaller diameter than the grinding roll 4 and is arranged on the side opposite to the tension rolls 6 and 7 with respect to the grinding roll 4,
The grinding roll 4 applies the required tension to the single-sided plated steel plate S1 between the tension rolls 6 and 7, respectively.
It is designed so that it comes into sliding contact with the As a result, a bus line of a steel plate having a horizontal U shape that slides into contact with the grinding roll 4 at two locations in the circumferential direction is set. And between the arrangement position of each of the pinch rolls 6, 7 and the opposing arrangement position of the grinding roll (main) backup roll 5u,
Between the tension roll 8, the grinding roll 4, and the backup roll 5d, there are double-sided plated steel plates S,
Water supply nozzles 9 are disposed above and below the moving area of the single-sided plated steel plate S1. Each nozzle 9
are each formed into a rod shape having a length equal to the width dimension of the double-sided plated steel plate S, and are oriented perpendicular to the transport direction of the double-sided plated steel plate S and the single-sided plated steel plate S1, and each spout is ground. Double-sided plated steel plate S toward grinding position A and B side by roll 4 and backup roll 5
, are disposed facing each side of the single-sided plated steel plate S1 in a non-perpendicular state. Each nozzle 9 is connected to a pump P whose suction side is connected to a water tank (not shown), and pressurized water from the pump P is applied to both sides of the double-sided plated steel plate S and the single-sided plated steel plate S1 at each grinding position and its surroundings. The grinding powder is sprayed toward the target to cool these surfaces and the grinding roll 4, and to remove the grinding powder by flowing out. CN is a control unit that controls the emission from a fluorescent The number of revolutions of the grinding roll 4 required to import data regarding the amount of residual zinc on the plated surface a'', detect the amount of residual zinc, and make it match the target value, and the number of revolutions of the grinding roll 4
The contact pressure of the grinding surfaces of the double-sided plated steel plate S and the single-sided plated steel plate S1, in other words, the position adjustment amount of the backup roll 5 with respect to the grinding roll 4, and the amount of water supplied from the nozzle 9 are calculated, and in order to realize this, the grinding roll Command signals are sent to the drive motor 4, the setting device of the backup roll 5, and the pump P.

After the chromate treatment, the double-sided plated steel sheet S is guided through the pinch roll 6 to the first grinding position A between the grinding roll 4 and the backup roll 5u, where it is sprayed with pressurized water from each nozzle 9. The surface to be ground is brought into pressure contact with the peripheral surface of the grinding roll 4 by the backup roll 5u so that the plated layer is ground away.

Then, the double-sided plated steel plate S that has passed through the first grinding position A reaches the tension roll 8 and is folded back, and is turned back to the grinding roll 4.
and the backup roll 5d, and while being similarly injected with pressurized water from each nozzle 9, the surface to be ground is polished by the backup roll 5d.
After the residual plating layer on the surface to be ground is removed by being pressed into surface contact with the circumferential surface, it is transferred to the coiler via the pinch rolls 7. In the above embodiment, the method of the present invention is applied to a continuous production line for single-sided plated steel sheets to remove the plating layer on one side of double-sided plated steel plates by polishing. Of course, it can also be applied to cases where In this case, the double-sided plated steel sheet may be fed from a payoff reel to the apparatus for carrying out the method of the present invention as described above, while the single-sided plated steel sheet from which the plating layer has been removed by polishing may be wound up from the apparatus onto a coiler. Next, the results of a comparative test between the method of the present invention and the conventional method will be shown.

The thickness of the sample material is 0.8T! T! 1t, board width 1.00
0r! Using the so-called Sendzimir method, in which both sides of a cold-rolled steel sheet are subjected to reduction treatment and hot-dip galvanizing (zinc coating amount: 45yId), the plating layer on one side is used for automobiles. The method of the present invention and the conventional method were carried out with the aim of achieving a residual zinc amount of 50 m91, which is the allowable upper limit for an exterior steel plate. The amount of residual zinc was detected using a fluorescent X-ray device. Table 1 shows the conditions for carrying out both methods. As is clear from Table 1, the operating conditions were exactly the same except for the number of grinding roll stands, and the amount of residual zinc obtained using the method of the present invention was better than that using the conventional method. Therefore, the method of the present invention, which requires only one grinding roll stand, is advantageous over the conventional method using two grinding roll stands because the number of stands is smaller and the space of the apparatus is correspondingly smaller. I understand. FIG. 3 is a schematic diagram showing another implementation state of the method of the present invention, in which two grinding rolls 4u, 4 are mounted on one stand.
d and two backup rolls 5u, 5d are arranged alternately in parallel upwardly and downwardly, and on one side of the stand is a tension roll 8u at the same level as the grinding roll 4u, and on the other side of the stand is a tension roll 8u. The grinding roll 4 has tension rolls 8d arranged at the same level as the backup roll 5d.
z of the double-sided plated steel plate S that contacts the grinding rolls 4u and 4d at three places, two places u and one place on the grinding roll 4d.
A shaped bus line is set.

The contact pressure of the double-sided plated steel plate S against the grinding roll 4u is adjusted by backup rolls 5u and 5d, and the contact pressure between the grinding roll 4d and the double-sided plated steel plate S is adjusted using a roll position setting device (not shown) on the grinding roll 4d itself. This is done by moving the camera closer to the backup rolls 5u and 5d. With such a device, first and second grinding positions A and B can be set between the grinding roll 4u and the backup rolls 5u and 5d, and between the grinding roll 4d and the backup roll 5.
A third grinding position C is formed between d and d, and one side of the double-sided plated steel plate S can be ground three times with a single stand, and a thicker plating layer can also be ground with a single stand. This means that it can be done.

In addition, each of the above-mentioned implementation states shows an example in which the method of the present invention is applied to the case of grinding the plating layer on one side of a double-sided plated steel plate, but the method of the present invention is applied to remove scale from a steel plate,
Of course, it can also be applied to rust removal, surface care, grinding of stainless steel plates, etc. As described above, with the method of the present invention, it is possible to grind a steel plate multiple times using a single stand, which not only reduces equipment costs but also reduces the space for equipment. The present invention has excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the case where the method of the present invention is applied to a continuous production line for single-sided plated steel sheets, Fig. 2 is a schematic diagram showing the equipment and control system for carrying out the method of the present invention, and Fig. 3 is a schematic diagram showing the method of the present invention. FIG. 4 is a schematic diagram showing another implementation state of the method. FIG. 4 is a schematic diagram showing an implementation state of the conventional method. 1... Reduction furnace, 2... Amount of molten zinc, 3... Chromate treatment device, 4, 4u, 4d... Grinding roll, 5u,
5d... Backup roll, 6, 7... Pinch roll, 8, 8u, 8d... Tension roll, 9...
・Nozzle, SO... steel plate, S... double-sided plated steel plate,
S1... Single side plated steel plate, CN... Control section.

Claims (1)

[Claims] 1. A method of grinding a steel plate using one or more rotationally driven grinding rolls, the method comprising: a single grinding roll circumferential surface;
A method for grinding a steel plate, which comprises setting pass lines for the steel plate to come in contact with each other at certain points, and grinding the steel plate by bringing the grinding surface of the steel plate into sliding contact with the peripheral surface of a single grinding roll twice.