JPS63132704A - Inline roll grinding method - Google Patents

Abstract

PURPOSE:To improve grinding efficiency, etc., by actually measuring a roll profile, roughly grinding the roll with a fluid mixture of a high pressure having large grain sizes of an abrasive material, and subjecting the roll to finish grinding with the abrasive grains of small grain sizes or the low-pressure fluid mixture. CONSTITUTION:A sand iron feeder 6 having storage tanks 12, 12' for sand iron having different grain sizes is provided and a high-pressure water feeder 7 is disposed. The roll profile is first measured by moving a distance sensor in the axial direction of the roll at a specified spacing therefrom. An unpassing part 4 to be ground at a larger amt. is then roughly ground R by injecting the high-pressure fluid mixture of the sand iron having the larger, grain sizes in the tank 12 to said part. The pressure of the fluid mixture is then lowered and the middle finish grinding F1 is executed; further, the finish grinding F2 is executed by the low-pressure fluid mixture of the sand iron having the smaller grain sizes in the tank 12'. The time for the grinding is thereby shortened, by which the grinding efficiency is improved and the surface roughness of the roll 1 is uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an in-line grinding method carried out within a rolling mill stand in order to adjust the surface of a roll worn by rolling into a predetermined shape.

(Prior art and its problems) As shown in FIGS. 1 to 3, as the amount of rolling increases, the rolling portion 2 of the rolling roll 1 wears out, especially at the end portion 3 of the rolling roll.
is becoming more intense. Such rolls must be ground to the initial profile. In this case, since the unthreaded portion 4 needs to be ground a lot, it takes a lot of time under certain grinding conditions, and rolling cannot be done during that time, reducing production efficiency. In order to achieve a desired finish roughness, grinding efficiency is poor and a lot of time is spent under certain conditions from the beginning.

Therefore, conventionally, as in Japanese Patent Application Laid-Open No. 60-30505, a number of water injection ladders having water injection nozzles are provided along the roll axis direction, and the pressure water injection pattern is determined according to the roll wear profile. A method has been proposed in which the roll surface is ground by increasing the pressure of water injection to areas where the degree of wear is low.

However, such a grinding method has the following problems.

(i) It requires a large number of nozzles, headers, and flow control valves, resulting in expensive equipment.

Qi) Since the water injection pressure differs along the roll axis direction, uniform surface roughness can be obtained in the roll axis direction. I can't. Furthermore, it is difficult to obtain the desired surface roughness.

(E) The amount of roll wear for each rolling is calculated and accumulated using the roll wear prediction model formula, the roll profile is predicted, and the amount of grinding is determined from this predicted roll profile and the ideal roll profile, so it is accurate. It is not possible to perform proper grinding.

This invention was proposed to solve these problems, and its purpose is to improve grinding efficiency and to
An object of the present invention is to provide an in-line roll grinding method that can easily obtain a desired surface roughness that is uniform in the axial direction of the roll, and can perform more accurate grinding.

(Means for Solving the Problems) The inline roll grinding method according to the present invention injects a mixed fluid of high pressure water and abrasive material from a nozzle, moves this nozzle in the roll axis direction, and rotates the roll. In an in-line roll grinding method in which the surface is ground in a rolling mill stand, the profile of the entire length of the roll is actually measured, and only the areas that require a large amount of grinding are roughly ground using a mixed fluid with high pressure and a large abrasive particle size, and then the grinding process is carried out. Finish cutting is performed using a mixed fluid with a smaller particle size or a lower pressure.

(Embodiment) The present invention will be described below based on an illustrative embodiment.

This is an example of using iron sand as the abrasive material mixed with high-pressure water jetted from a nozzle.As shown in Figures 4 and 5, the higher the pressure and the larger the iron sand particle size, the greater the amount of grinding. , since the surface roughness is rough, in the present invention, the unthreaded plate part 4, which requires a large amount of grinding, is first rough-ground R with a mixed fluid having a large particle size and high pressure.
Next, the pressure is lowered and semi-finish grinding F1 is performed, and then the grain size is reduced and finish grinding F2 is performed.

Fig. 6 and Fig. 7 show an example of a device that performs such grinding, and includes a mixing nozzle 5 that mixes high-pressure water and iron sand and injects it toward the roll surface. a high-pressure water supply device 7 that supplies high-pressure water to the mixing nozzle 5; a hydraulic cylinder 8 that moves the mixing nozzle 5 in the roll axis direction; and a hydraulic device 9 that operates the hydraulic cylinder 8. It is composed of a distance sensor 10 that actually measures the roll profile, and a control device 11 that controls the device.

The mixing nozzle 5 is composed of an injection nozzle section 5A and a mixing nozzle section 5B, as shown in FIGS. 8 and 9.

The iron sand supply device 6 has tanks 12 and 12' for storing iron sand of different particle sizes, and uses compressed air A to forcefully feed the dried iron sand to the mixing nozzle 5, and also uses a switching valve 13 to perform rough grinding, R2, and finish grinding F, respectively. Two tanks according to 12.
Select 12'.

The high-pressure water supply device 7 has a pump P, a pressure adjustment valve 14, and a three-way switching valve 15. The required pressure is selected by the pressure adjustment valve 14, and the water is supplied to the mixing nozzle 5 through the three-way switching valve 15 during grinding. It is designed to send high pressure water.

The hydraulic system 9 includes a pump P, a pressure regulating valve 16. Servo valve 1
7, and the servo valve 1 adjusts the moving speed of the mixing nozzle 5.
Do it by 7. Further, the position of the mixing nozzle 5 is controlled by a position detector 18 such as a Magnescale 18A connected to the piston rod of the hydraulic cylinder 8.

The distance sensor 10 uses an optical displacement sensor consisting of an LED beam and a light receiving element, and is movable forward and backward by a hydraulic cylinder 19. Like the mixing nozzle 5, it is attached to the rod end of the hydraulic cylinder 8, and is movable in the roll axis direction. .

Next, the present invention will be described in detail using specific numerical values.

First, measure the roll profile before grinding. This measurement is performed as follows based on a program installed in the control device 11 by turning on the roll profile measurement switch on the operation panel.

(i) The hydraulic system 9 is activated and the pressure and oil amount are adjusted to a predetermined level. In this case, the pressure is set to 3 Q Kp/d and the oil amount is set so that the moving speed of the nozzle 5 is 1000 mm/min.

Middle) This oil pressure acts on the hydraulic cylinder 19, and the distance sensor 10 approaches the roll surface. In this case, the stroke of the hydraulic cylinder 19 is set in advance in accordance with the roll diameter so that the distance between the distance sensor 10 and the roll surface is approximately 5 mm.

(e) After the timer confirms that the distance sensor 10 approaches the roll surface, the hydraulic cylinder 8 is activated. As a result, the distance sensor 10 moves in the roll axis direction,
Measure your role profile. This roll profile is obtained from the gap S between the distance sensor 10 and the roll surface and the detected value of the position detector 18 that measures the amount of movement of the hydraulic cylinder 8. This measurement pitch is performed at five pitches.

(b) Through the above steps, a profile as shown in FIG. 1 is obtained. Here, rough grinding, semi-finishing grinding, and finishing grinding are determined based on the dimensions of steps A and H.

For example, if A≧0.0051uIL, rough grinding 0, 0.03≦
If A<0.005B, semi-finish grinding; if A<0.003, finish grinding.

Note that the case of 8 dimensions is also the same as the A dimension.

Further, after the measurement in (E) is completed, the hydraulic cylinders 8 and 19 are returned to their original positions by the servo valve 17.

After measuring the roll profile as described above, when the grinding switch on the operation panel is turned on, the grinding according to the program of the control device 11 is performed as follows.

(i) The high-pressure water supply device 7 and the hydraulic device 9 operate.

Oi) Determine the amount of grinding from the ideal profile after grinding and the measured profile. The amount of grinding is calculated based on the roll diameter, grinding diameter, and axial distance. The axial direction is calculated at a pitch of 10M.

(E) Perform rough, semi-finish and finish grinding according to the dimensions of steps A and B in Figure 1. In this case, the movement speed of the nozzle 5 is kept constant, and the movement distance and number of movements are changed.

For rough grinding, abrasive particle size: 0.3 pressure crab 700Kp/cII! use. In this case, the grinding roughness will be approximately Ra 7 μm.

Next, when performing semi-finishing, the particle size of the abrasive is 0.3 m and the pressure is 500 Kp/c1fl.The particle size is the same as that for rough grinding, and the pressure is lowered. In this case, the grinding roughness is approximately Ra5 μm.

Next, the finish grinding is carried out at the same pressure as the rough finishing pressure, with the grain size of the abrasive being reduced to 700 to 9/cr/l. In this case, the grinding roughness is approximately Ra2 μm.

Here, the pressure is converted by the pressure regulating valve 14. Adjustment of zero pressure is made in advance so that it can be converted to 700,500 Kp/d. In addition, the particle size of the abrasive can be changed by tank 1.
At 2.12', particles of particle size 0.3 and 11Jx are stored and used depending on the switching valve 13.

The pressure of the compressed air that pumps the abrasive material is 5 KP/crrf
The amount of abrasive transported, which is constant, is determined by the opening of the switching valve 13, but based on the actual grinding results, the opening is set at 3 Kp/min.

If particularly necessary, it is also possible to adjust the opening degree.

If the amount of transportation is increased, the amount of grinding will also increase, and if it is decreased, the amount of grinding will be decreased. The moving distance is made movable in 10-inch pitches, and the position is determined by the position detector 18 used for profile measurement.

Further, the roll rotation is 1 o rpm or more.

Note that after grinding, the roll profile is measured in the same manner as before the start of grinding, and the amount of grinding is confirmed.

In addition, although the above example shows an example of changing the pressure and particle size, it is also possible to perform rough, semi-finishing, and finishing grinding by keeping the pressure, high-pressure water volume, and nozzle moving speed constant and changing the particle size. Alternatively, the grinding may be performed while keeping the nozzle moving speed and particle size constant and switching from high pressure to low pressure.

Furthermore, it is also possible to perform the process while changing the moving speed of the nozzle. In this case, a servo valve is used to adjust the speed, and the speed is changed in the axial direction according to the amount of grinding.

Further, the abrasive material is not limited to iron sand, but other abrasive materials can also be used. In this case, it is necessary to record data as shown in FIGS. 4 and 5 before grinding.

Next, the results of application to a roll with a roll diameter of 7QQmx and a body length of 1800 mm will be shown.

Normally, the rolls wear out after 2000 tons, so the rolls are replaced. In addition, the same board width is approximately 200 tons (approximately 10 slabs)
Rolling for more than 100 sheets causes shape defects, so currently rolling is performed on a schedule from wide sheets to narrow sheets.

Therefore, every time about 200 mm is rolled, the unworn part of the unthreaded plate part is made into a pressure cuff 00 of 97 Crd and the iron sand grain size is 0.
3 myn, rough grinding with a grinding allowance of ψ10 μm, and then
The pressure was reduced to 500 Kp/7 and semi-finish grinding was performed with a grinding allowance of ψ3 μm, and the grain size was further reduced to 0. lQw, finish grinding was performed with a grinding allowance of ψ1 μm to obtain a surface roughness of 2 to 3 Raμm, and as a result of rolling with this surface roughness, even if the rolling amount was 2.5 times that of 5000, the rolling amount was still There were no problems in terms of quantity. In addition, it is now possible to roll sheets from narrow widths to wide widths, and schedule-free rolling has become possible, whereas conventionally rolling was done by setting a schedule for sheet width.

As a result, slabs of the same width can be directly rolled (D
/R), or heat the slab as it is and roll it (H/C
) became possible.

The grinding conditions other than those mentioned above are as shown in Fig. 10.
The distance l between the roll 1 and the nozzle 5 is 100, the collision angle θ of the jet water with the roll is 60°, and the amount of high-pressure water discharged is 401/m.
in, the iron sand supply rate is 3 to 2/min.

(Effects of the Invention) As described above, according to the present invention, the profile of the entire length of the roll is actually measured, only the portion where the amount of grinding is large is roughly ground with a mixed fluid having a high pressure and a large abrasive particle size, and then the abrasive particle size is Since finishing cutting is performed using a mixed fluid with a smaller or lower pressure, it is possible to improve grinding efficiency and easily obtain a desired surface roughness that is uniform in the direction of the roll axis.

In addition, since the profile is actually measured, accurate grinding can be performed.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a roll showing the grinding method according to the present invention, FIGS. 2 and 3 are side views and front views showing the rolling state, and FIG. 4 is a graph showing the relationship between pressure and grinding amount. Fig. 5 is a graph showing the relationship between iron sand particle size and surface roughness, Figs. 6 and 7 are a schematic side view and a schematic plan view showing an apparatus for carrying out the grinding method of the present invention, and Fig. 8 is a graph showing the relationship between iron sand particle size and surface roughness. FIG. 9 is a sectional view showing the mixing nozzle, FIG. 9 is a sectional view taken along the line IX-IX in FIG. 8, and FIG. 10 is a side view showing the nozzle installed. 1. Roll, 2. Threading section 3. Threading end, 4. Unthreaded section 5. Mixing nozzle, 6. Iron sand supply device 7. High pressure water supply device, 8. Hydraulic pressure. Cylinder 9...Hydraulic system, 10...
Distance sensor 11...control device, 12.12'
・Tank 13...Switching valve, 14...Pressure regulating valve 15...3-way switching valve, 16...Pressure regulating valve 17...Servo valve, 18...Position detector 19...Hydraulic cylinder

Claims (1)

[Claims] (1) In an in-line roll grinding method in which a mixed fluid of high-pressure water and abrasive material is injected from a nozzle, the nozzle is moved in the roll axis direction, the roll is rotated, and the roll surface is ground in a rolling mill stand. Measure the profile of the entire length of the roll, perform rough grinding only on the part that requires a large amount of grinding using a mixed fluid with high pressure and a large abrasive particle size, and then finish cutting with a mixed fluid with a smaller abrasive particle size or a lower pressure. An inline roll grinding method characterized by: