JPS63134171A - Grinding method - Google Patents

Abstract

PURPOSE:To eliminate a loading phenomenon in a grindstone as well as to make stable grinding capacity securable all the time, by making pressing force of the grindstone larger as long as for a short time in the midway of grinding operation. CONSTITUTION:It is altered by pressing force P1 through which grindstone life is suddenly decreased at each specified time during grinding operation by the specified pressing force P0, whereby grinding takes place with this P1 force as long as for a short time, and a stone surface where loading is produced is purposedly omitted and new abrasive grains are produced. In consequence, these new abrasive grains are producible on the stone surface all the time so that stable grinding capacity Vga is securable.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a grinding method, and is particularly useful when applied to online grinding of work rolls of a hot rolling mill.

<Prior Art> FIG. 2 shows online roll grinding in which a work roll 1 of a hot rolling mill is ground online using a grindstone 2. As shown in FIG. 2, a plurality of grindstones 2 are arranged in the axial direction of the roll 1, and the roll 1 is ground while each grindstone 2 is oscillated by a predetermined amount in the axial direction of the roll 1.

<Problem to be solved by the invention> In such grinding, the pressing force P of the grinding wheel 2 against the four wheel 1
The relationship between G, grinding wheel life G, and roll grinding capacity V is shown in FIG. 3. In other words, when the pressing force P is increased, the grinding ability Y of the roll increases, but conversely, the wear rate of the grindstone increases and the life G decreases. Therefore, in actual operation, a pushing car with a balance between life G and grinding capacity V is used, and life G
0. Grinding ability V. It is best to perform grinding operations with However, in the case of grinding with the grindstone 2, by grinding for a long time, the abrasive grains themselves, tar chips, etc. adhere to the contact surface of the grindstone 2, causing a clogging phenomenon and reducing the roll grinding capacity vgl. This phenomenon is shown in FIG. Here, 1g indicates time. This phenomenon causes a difference in the amount of roll grinding within a predetermined period of time, which interferes with planned grinding and rolling.

The present invention provides a grinding method that eliminates this clogging phenomenon and always provides stable grinding performance V.

Means for Solving the Problems> The present invention for solving the above problems is characterized in that grinding is performed by intermittently increasing the grindstone pressing force P to a region where the grindstone life G rapidly decreases.

Effect> By grinding with a large pressing force for a very short time during grinding with a predetermined pressing force, the clogged grinding wheel surface is intentionally dropped and a new abrasive grain surface is created, and the clogging is constantly avoided. You can get stable grinding ability.

Embodiment Example FIG. 1 shows an embodiment. As shown in the figure, in the method of the present invention, during operational grinding with a predetermined pressing force P0, the pressing force is changed at predetermined time intervals to a pressing force P1 at which the grinding wheel life G sharply decreases, and grinding is performed with a force P for a very short period of time. New abrasive grains are generated by causing the contact surface of the grindstone to fall off. According to this method, new abrasive grains can always grow naturally on the grinding wheel surface, resulting in stable (average) grinding performance v9. is obtained.

The pressing force P0 shown in FIG. P, and G,v.

Although it varies depending on the grindstone material and shape, an example of the experimental results is shown below. The roll was made of nickel-grain material with a diameter of 600 mm and an axis length of 1800 m+a, and the grindstone was cup-shaped and made of GC100K material with a diameter of 240 mm and a diameter of 80 mm. Roll speed v, == 60
Normal grinding pressing force P at 0 alpm. = 150 kg, high pressing force P, = 200 kg, and as a result of grinding in a pattern where grinding with Pl is performed for 6 seconds every 120 seconds of grinding with Po, vg = 0.1 ~ as shown in the example shown in Fig. 1. v between 0.13
, = 0.015/rev, stable results were obtained, and the effectiveness of the present invention was verified.

Here, the nickel-grain material is a cast iron material mainly used as a hot-rolled finish roll material, and the main component is C=
3.0-3.5%, Si<1.5%, N i = 2
．． 0-4.5%, Cr=0.5-1.5% pMo<
It is 0.5%. Furthermore, the grindstone GO material is an abbreviation for carbon-based abrasive grain material, and is an international standard product.

Now, let's talk about the effects of the present invention. First, since grinding is performed in an area where the pressing force is small, V is small and G is large. At this point, since the pressing force is small, clogging is likely to occur, but at this point, the pressing force is increased to forcibly reduce G and increase v to cause the abrasive grains to fall off, so this clogging can be prevented. After that, grind again with low pressing force. However, at this time) must satisfy the required value. This method has a longer grinding wheel life, is more economical, and requires fewer grindstone replacements than grinding with a high pressing force that always prevents clogging.In addition, in the case of a high pressing force, the grinding capacity V
Because of the large amount of grinding, the time required to grind a given amount is short, usually 3
Compared to 0 second grinding, it takes 3 to 5 seconds, and there is a drawback that it is difficult to obtain a uniform coated surface, but this could be solved by reducing V.

<Effects of the Invention> According to the present invention, stable grinding performance can be obtained at all times, and grinding can be performed under conditions where the life of the grinding wheel does not deteriorate at all compared to conventional methods, so stable grinding and rolling can be achieved as planned. Operation becomes possible. In addition, the life of the grinding wheel is extended, which increases the economic effect, and the grinding capacity V is so large that the grinding time for a given amount is as short as 3 to 5 seconds, whereas the grinding time is about 30 seconds. Uniform roll surface grinding is now possible.

[Brief explanation of the drawing]

Figure 1 is a characteristic diagram showing an embodiment of the grinding method of the present invention, Figure 2 is a characteristic diagram showing an embodiment of the grinding method of the present invention.
The figure is a configuration diagram showing an online roll grinder, which is one of the objects of the present invention.
FIG. 4 is an explanatory diagram showing the relationship between grinding abilities, and is a characteristic diagram showing an example of a conventional grinding method. In the drawing, 1 is the work roll, 2 is the grindstone, P is the pressing force, V is the grinding capacity, [ is time, and G is the life. Patent applicant Mitsubishi Heavy Industries Co., Ltd. Ryomei Giken Co., Ltd. Representing agent

Claims (1)

[Claims] A grinding method characterized by increasing the pressing force of the grindstone intermittently for short periods of time during grinding by pressing the grindstone against the workpiece with a predetermined pressing force.