JPS58209401A - Rolling device - Google Patents

Abstract

PURPOSE:To prevent the sustained heat overload state in the motors of rolling mills in roughing and finishing mills for rolled materials discharged from a heating furnace by controlling the discharging pitch of the rolled materials in accordance with the monitoring of the heat load state in the motors of the respective rolling mills. CONSTITUTION:A rolled material is discharged from a heating furnace 1 with a discharging machine 2 and is rolled in vertical roughing mill groups 4, 3, whereafter the material is rolled with a finishing mill group 5 and is coiled on a coiler 6. A rolling schedule is set with a calculator 8 and the heat load state of a rolling mill motor 9 is monitored with a device 20. Since the heat load state of the motor 9 is expressed in the ratio of a rated current value to the mean square current value RMS of the motor 9, the RMS can be decreased simply by increasing the non-rolling time, that is, the discharging pitch of the rolled materials. Therefore, the discharging pitch may be determined in such a way that the RMS of the motors to be monitored is determined by the equation and that all thereof are so set as to be kept within the permissible RMS. The monitoring of the RMS is accomplished by measuring the current value of each rolling mill in a specified period, and determining and checking the RMS from the start of the previous rolling at every start of rolling with each rolling mill.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating furnace for a rolled material, and a rolling apparatus for extracting and rolling a J-rolled material.

Figure 1 shows a conventional hot thin plate rolling machine; the peak is the heating furnace, and Q)
is a heating furnace (1), an extractor for extracting the rolled material, and a filter (filter).
)-(3d) are rough EE rolling mills, (4a)-(4b) are vertical rolling mills, and (5a) to (5f) are finishing EE rolling mills. The winding machine (7) winds up the rolled moon, and the finishing rolling machine (5a) to (nails) and the conveyor
a control device for a motor that drives the feed table (60), (8
) is a rolling schedule calculation device fR, (10) is a scale breaker, (11) is a winding machine control device that drives and controls the winding machine (6) that winds up the rolled material, (12 piece extractor ( 1). Fig. 2 shows a conventional plate rolling apparatus for rolling thick plates. The same reference numerals as in Fig. 1 indicate the same or corresponding parts, and (13) indicates the rough thickness. The plate rolling machine (15) is a finishing thick plate rolling machine, and each EE in these conventional hot thin plate rolling equipment and thick plate!E rolling equipment is
The rolling mill adjusts the roll opening, roll rotation speed, and rolling speed for each product.
A rolling schedule that sets appropriate values for the number of rolling passes of the reversible rolling mill, the number of roll rotations during biting, and the number of roll rotations during biting and releasing is calculated by the calculator (8) K, and the rolling schedule is calculated by the computer (8) K for each rolling pass. and control of the conveyor table (60) before and after the rolling mill,
Regulatory (goods) device (7) [Performed by.

At this time, conventionally, in order to determine the rolling schedule, the schedule that allows rolling for the shortest time with the minimum number of passes has been selected.

In a rolling mill, if the rolling temperature, rolling speed, inlet plate thickness, outlet plate thickness, and inlet plate thickness are given, the required rolling force F, required power per roll, and roll The opening degree S is determined.

F-fl (H, h, 'r, N, R,,w)
(11 Houman fz (H, h, F, R,)
+21S = fm(h,F)
131 Here, the maximum rolling method, maximum power, and maximum rolling amount are determined based on the characteristics of each rolling mill, so if the schedule for each rolling bus' is determined with the maximum power of each rolling mill as the target, the maximum The number of passes and rolling time possible. However, in the finishing mills (5) and (1'5), the rolling pass schedule is usually determined based on the crown value (plate finishing) in order to perform rolling for the shortest time.

This is because in finishing rolling, reversible rolling is not performed and one rolling mill performs only one final pass for thick plates, or for thin plates, several successive rolling mills are used one after the other to finish rolling. Because of this operation, the rolling time is determined by the length of the material and the amount of reduction in plate thickness due to rolling.For this reason, there is no advantage to calculating a rolling schedule that aims for the shortest rolling time. , the rolling schedule is determined with the goal of finishing υ accuracy and product quality accuracy.

In any case, in determining these rolling schedules, calculations have been made to satisfy the specification limits of the rolling mill, such as the rolling power, but conventionally the heat load of the rolling mill motor has not been taken into consideration. Ta.

This means that the heat load of the rolling mill motor exceeds the specification limit by, for example, 10
This is because even if the motor exceeds the limit, it will not directly cause a motor failure at that point.

However, if the heat load continues to be excessive, the insulation performance of the rolling mill motor will deteriorate, leading to malfunction of the rolling mill motor.

This invention was made in view of these points,
It is an object of the present invention to provide a rolling equipment in which the operation of a rolling mill motor is always controlled in an appropriate state without continuing an overheated load state.

A hot rolling apparatus as an embodiment of the present invention shown in FIG. 3 will be described below. In FIG. 3, the same reference numerals as in FIG. 1 indicate corresponding parts, and the explanation thereof will be omitted. (9) is a rolling mill motor that drives the rough rolling mill (6);
(20) is a monitoring control device that monitors the heat load state.

The next π operation will be explained. After the rolled material is heated to a predetermined temperature in the heating furnace (1), it is taken out onto the conveyance table (60) by the extractor (21) and placed on the scale breaker (1).
0), vertical rolling mills (4a) to (4d), and rough rolling mill (
6a) to (3d) After being rolled to a predetermined thickness at jC,
The plate is rolled to the final thickness in finishing rolling machines (5a) to (5f).

This rolled material is rolled by coil winders (6a) to (6C).
) is wound into a coil.

By the way, the thermal load state of the rolling mill motor (9) is expressed by the ratio of the rated current value to the root mean square current value of the rolling mill motor θ). The root mean square value of the above current is calculated using the following 4 formula t
tc, cj) is represented.

However, RMS4 = i rolling mill motor current root mean square value l1
= a = instantaneous current value of rolling mill motor' IoJ = i rated current value of rolling mill motor τ =
It is monitoring time. As is clear from these four equations, if the monitoring time τ is constant, in order to lower the current root mean square value 11M8i,
It can be seen that the current 11 of the rolling mill motor only needs to decrease.

Therefore, it is sufficient to reduce the load on the single rolling mill motor, and therefore it is unnecessary to carry out rolling.

By the way, in order to utilize the capacity of the rolling line to the fullest, rolling should be carried out one after another on the rolling line without collision between the previous rolled material and the next rolled material. Well, that's why.

In such a state, the current of one rolling mill shows changes as shown in FIG. (60 quasi-current change curve, (32)*
When z BE i, (61),, (rolling is performed -Cz
When not, (36) indicates stop.

At this time, roll to lower the root mean square value of the current.

What is necessary is to lengthen the time (61) during which the When extracting the rolled material from the heating furnace (1), it is only necessary to lengthen the extraction pitch.

Therefore, the extraction pitch is the RMS of the rolling mill motor Q) to be monitored.
The value may be determined using 4 formulas, and 5 may be determined so that all of the values are within the allowable current root mean square value of 111'vi8o1.

Now, if τ in equation 4 is the time from the start of rolling of one material to the start of rolling of the next material for each rolling mill, the amount of correction of the extraction pitch determined from the thermal load is calculated by the following equation 11M5oi=I
Maximum allowable current of iE rolling mill motor square Hiratsuka τi = a
The rolling start time of rolling mill E and the time it takes to start rolling the next material. Therefore, I! The amount of correction for 1 pit (1E rolling mill motor, which is the largest among 71) is taken as the amount of correction from the heat load, and other factors such as collision prevention between materials on the line and the top condition of the materials in the heating furnace are considered. You can decide. Next, extract pitch performance K
[I would like to add.]

The rolling schedule is calculated by the rolling schedule calculating device (8) as follows. The rolling specifications of the rolled material are input to the rolling schedule calculation device (8)K for each rolled material. This is given by the dimensions of the rolled material, slab temperature, material, target dimensions after rough rolling, final coil dimensions after finish rolling, finish exit temperature, rolling speed of the final stand, and load distribution ratio of each rolling mill. It will be done. On the other hand, the equipment manufacturer for each rolling mill is determined in advance. These are the work roll diameter of the rolling mill, the maximum rolling speed, the rolling force limit, the rolling power limit, and the maximum rolling amount.

Based on the specifications given above, the calculations are performed as follows.The rough rolling mill (31K is the rough rolling mill 6) where the schedule is calculated separately for the total rough rolling mill 6) and the finishing mill (E rolling mill) (5). ) is given a power-thickness curve, which is called a power curve.This is expressed by the following equation.

PW = fig(h, ho, Wo, ni, )
(61PW: Cumulative value of rolling power h: Target plate thickness ho; Initial plate thickness Wo: Initial plate width 5: Material 1) If this is expressed graphically, it becomes Figure 5 (40) is the power curve.

The entrance plate thickness ho of the total rough rolling mill (3) and the outlet plate thickness hR of the rough rolling mill (3) are given. According to the power curve, it is required for rough rolling. The cumulative power 1'WR is determined. Once this cumulative power I'WR is determined, this power distribution ratio is α1゜α2
．． α3. α4 is given to each rough rolling mill (6a) to (3d), so the cumulative power FWR is given to each rough rolling mill (3a) at a distribution ratio.
H3J) as shown in Figure 5, each rough rolling mill (3
) can determine the exit side plate thickness. Therefore, the plate thickness at the exit side of the rough rolling mill (3) can be determined. Therefore, the plate thicknesses at the entrance and exit sides of the rough rolling mill 6) are determined.

Next, since the rolling speed of each rough rolling mill 43) is given, the time required for the material to reach each rough rolling mill (3) is determined. This is because the operating speed pattern of the conveyor table is fixed, and only the speed during rolling is a speed synchronized with h' - rolling speed! In can do it.

If the transfer time is known, the material temperature that decreases due to radiant heat during that time is Toui' = f (i'in, Il, cp,
γ, t) TouT; Output temperature 'll'ln: Inlet temperature [(: Plate thickness Cp: Material specific heat γ: Material density t: Determined in time. Therefore, the FE rolling temperature at which the rolling temperature can be predicted is determined. Since each part on the right side of Equation 1 is known, the rolling force F is found, and the roll opening degree is determined from Equation 6.The rolling schedule for the thickness K is obtained, and then the vertical rolling mill The medium rolling schedule based on (4) can be calculated.

Now, given the slab medium and rough output target medium, each bus lE
The amount of expansion in the width direction due to extension can be calculated using the following formula.

6Wi = f2゜(r(i, hi, Wl, at
, 'rt, Di) △WI: Medium wave thickness Hl: Inlet plate thickness 111: Outlet plate 19 ~ li, Hard rolling mill height 1 tentative + 4] E1: Hard rolling mill vertical height, 1゛I: Rolling temperature Kawa: The diameter of the work roll, and therefore the total amount of "1" cut in rough rolling, is given by the following formula:

F3R= Wo -WR+f aW1 -1 BH,: Rough FE rolling total fIJ cutoff νVo: Slab width Wll, : Mill width N; Rough rolling pass number King (
If assigned to 4a) to (4d), this vertical rolling mill (4a)
The amount of reduction in ~(4d) cannot be determined. Once the rolling reduction amount is determined, the rolling force and opening degree can be determined using the same formula as for horizontal rolling.

Since the finishing mill (5) is a continuous rolling mill, the final plate thickness and the speed of the final finishing rolling mill (5f) are given, so the constant volume law applies and can be determined once the plate thickness of each rolling mill 6) is determined. That is, hi ・Vi = hv −VF hi: i Rolling machine outlet side plate thickness Vi: i Rolling machine rolling speed hF: Finished outlet side plate thickness vF: The final finishing mill speed holds, so it is only necessary to find the rolling pattern. As with rough rolling, it can be determined by giving the Nihaha curve width, the finished input side plate thickness, finished finished plate thickness, and the load distribution ratio of each rolling mill.

Therefore, once the speed is determined, the rolling temperature can be calculated from the arrival time to the rolling mill, and then the rolling force is determined, the rolling position of each rolling mill is determined, and the schedule calculation is completed.

Based on this schedule meter Rough rolling and finish rolling.

On the other hand, the current root mean square value of the rolling mills is monitored by measuring the current value of each rolling mill at regular intervals, and each time each rolling mill starts rolling, the current root mean square value from the previous rolling start is calculated and checked. After checking, the extraction pitch correction amount is determined and the current extraction pitch is corrected.

Although the above example describes a hot thin plate rolling machine,
The same method can be applied to a plate rolling mill.

It is also effective to check the flow root mean square value not every time rolling is started, but at regular intervals, such as every 20 minutes.

As described above, according to the present invention, the thermal load state of the rolling mill motor is monitored, and the extraction pitch of the rolling mill is controlled based on the result of this monitoring, so that the rolling mill motor can be used in an appropriate state. This has the effect of extending the life of the rolling mill motor.

[Brief explanation of the drawing]

A current change curve showing the current change of the machine motor, and FIG. 5 is a curve diagram showing the plate thickness versus required movement. In the figure, (1) is a heating furnace, Q) is an extractor, and (6a) is a heating furnace.
~('ld) is a roughing mill, (4a)-(4d) is a vertical rolling mill, (5a) (5f) is a finishing mill, (6a)-(6c)
(c) winding machine, (7a) to (7b) are rolling mill and motor control devices, (9a) to (9e) are rolling mill motors, (8
) is a rolling schedule calculation setting machine, (20) is an IE rolling mill motor heat load monitoring device, (21) is an extraction machine control device, and (22) is a winding machine control device. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno - 11', it,: I'+ Length 1″Xhsl,
-1t /'l Noah 2 a 7. l'Q(
ill, 'I 57-9i666 No. 2 Koreaki no N, (Ro, Rolling equipment: (1 Yamamasa = 4 = 11 Relationship with f'l T'r + i' + Out ■ 1 person fi
Place East I: I Tocho・((l11kumaru0mej
``112-3'I; Name ('+: (for 6+ Mitsubishi Shinki Co., Ltd. Representative h Katayama f2 8 Department 4 Agent fl:, Place Heavy Industries: [Tocho-dai 111-ku Marunouchi 21°112-3 5, within Mitsubishi Electric Corporation, each column of [vr Revised Claims 1 and 1 - Detailed Description of the Invention] of the amended 71-part specification and drawings 4 6, Contents of the amendment 1) "Patent of the specification" 2) In the specification, page 3, line 20, [Claims 1] should be amended as a separate sheet.
It's already decided. ” he corrected. 3) IF "1 over state 9 @" on page 4, line 17 of the specification as "over state 1". 4) Correct "-" on page 7, line 10 of the specification to "-τ1". 5) Complement IF "Determined. Next K" on page 7, line 1, line 7 of the specification as "Determined, next." 6) Correct the phrase [I-, I-on-barreled] on page 8, lines 11 to 14 of the specification as follows. [From the specifications given above, perform n as follows. Schedule calculations are performed separately for the full set rolling mill (3) and the first rolling mill (5). Rough rolling mill (3) ° is rough rolling, the power-thickness curve for mill (3) is given, J7
) Specification No. 900, line 2) [-1, which is the figure of 5, becomes 1, figure 5,'' and supplement iF'. 8) Correct "reeruru." on page 9, line 5 of the specification to [-1 if it is obtained. 9) "require" on line 6 of page 9 of the specification. Let the cumulative power l be the "required cumulative power". 10) Delete "Therefore, it can be determined." from page 9, line 11 to line 12 of the specification 1, 11) [Only the speed is rolling] on line 17 of page 9 of the specification
Delete. 12) Add 1 hour J on page 10, line 8 of Akira Tanuki 1 Yoi to [exposure time 1]. 16) In the 9th line, 6th line of the specification, 1 "It can be predicted" is supplemented with "It can be predicted." iE. 14) mm book, page 16, line 16, "It has the effect of extending the lifespan." fK: "It has the effect of extending the lifespan." 15) Figure 5 of the drawing is attached as a corrected drawing. Correct it. Scope of Claims (Amendment) [The pressure +tn produced from the heating furnace by the extractor is rolled in a rough rolling mill and then further rolled in a finishing mill.] Monitoring Judgment 1 by determining the root mean square value of the electric current of each rolling mill motor of each rolling machine of the roughing and finishing mills, and determining the extraction pitch of the IF rolled material based on the results of this monitoring judgment. A rolling mill characterized in that it is provided with a means for controlling the

Claims (1)

[Claims] In the case where the rolled material taken out from the heating furnace by the extractor is rolled in the roughing mill and then passed through the finishing mill to form the plate into a predetermined thickness, the heat load of each rolling mill motor of the roughing and finishing mills is A rolling apparatus characterized by comprising means for determining and monitoring the root mean square value of the current of each of the rolling mill motors, and controlling the extraction pitch of the rolled material based on the result of the monitoring and judgment.