JP3480407B2 - Retention force calculation device and rolling abnormality detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retend force calculation for calculating a rolling retentive force value of a motor for feeding a rolling material to a plurality of roll stands of a mandrel mill for rolling a seamless pipe, each time passing through each roll stand. The present invention relates to an apparatus and a rolling anomaly detection apparatus capable of early detection of rolling anomaly occurrence by the retentive force computing apparatus.

[0002]

2. Description of the Related Art For example, in a mandrel mill used for manufacturing a seamless pipe, due to improper application of a lubricant to a mandrel bar, defective rolling position setting of a rolling roll, rotational speed setting error of a rolling roll, etc. For example, a rolled material is compressed between roll stands of a mandrel mill to form a wrinkle, or conversely, excessive tension is applied to the rolled material to cause a rolling abnormality such as thin-walled rolling. When a rolling abnormality occurs, there is a case where the rolling is stopped and a measure is taken for a long time.

Conventionally, a rolling abnormality is detected by detecting an overcurrent of a motor for driving a rolling roll or a motor for driving a mandrel bar, and a rotation speed and a driving current value of a motor for driving a mandrel bar ( (A torque current value) is detected, and a rolling abnormality is determined when it does not exist within a predetermined allowable rolling abnormality range of the mandrel mill for a predetermined time or longer (for example, actual Kaihei 3-9203).
No.) is known.

That is, in Japanese Utility Model Laid-Open No. 3-9203, as shown in FIG. 4, for example, the allowable value β defined for the torque current value is a value at which it is possible to judge that a rolling abnormality has occurred, that is, + (positive side). ), The motor is in the power running state, and the torque applied to the motor is determined to be excessive.

[0005]

However, in the above-mentioned conventional method, the detected torque current value includes factors such as mechanical loss torque and acceleration / deceleration torque of the mandrel bar drive system that vary regardless of rolling. Therefore, in detecting the rolling abnormality, the torque current value depends on the above-mentioned factors that vary regardless of rolling.
Even if the set value β shown in (1) is set, it is not accurate whether or not the factors involved in the rolling itself have changed, and there is a problem that the rolling abnormality cannot be detected accurately and early.

Further, in the conventional method, after a rolling abnormality occurs and the allowable value β is exceeded, the rolling abnormality is detected T2 hours after the time setting T2. Since it took a long time to detect rolling abnormalities, there were cases where wrinkled and shredded rolled materials remained in the mandrel mill. When such a situation occurs, there is a problem in that the rolled material must be removed by gas cutting, resulting in a loss due to the facility being stopped for a long time.

The present invention has been made to solve the above problems, and the torque of a motor involved in rolling itself can be calculated as a rolling retentive force value to obtain a detailed and proper behavior of the motor. Retention force calculation device,
Another object of the present invention is to provide a rolling anomaly detection device capable of accurately detecting a rolling anomaly by monitoring the rolling retentive force value calculated by the retentive force computing device.

[0008]

In order to achieve the above-mentioned object, the retentive force computing device of the present invention constantly computes the retentive force value of the motor in the computing unit, and immediately before the rolled material is caught in each roll stand. The retentive force value when the signal of is input is stored, and the stored retentive force value is stored.
The calculates the clipping position immediately before Ritendo force value and the torque of the machine loss in is from the Ritendo force value and the bite immediately before Ritendo force value calculated always had to be computed rolling Ritendo force value.

By doing so, the rolling retentive force value obtained by the calculation removes the torque and acceleration / deceleration torque corresponding to the mechanical loss that fluctuates irrespective of the rolling. It can be used as the true torque element of the motor to be used, and it becomes possible to grasp the rolling behavior in detail and appropriately.

Further, the rolling anomaly detecting device of the present invention has a retentive force calculating device, and detects a rolling anomaly by comparing the rolling retentive force value calculated by the retentive force calculating device with a preset allowable value. because it is so, it is possible to detect reliably and early abnormal rolling each time it rolled at each roll stand, not only to minimize the equipment damage, torn material stop machine such as a stop due to occurrence Time loss can be minimal and minimal.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION
It is a retentive force calculation device that calculates the torque of a motor that feeds rolled material to a plurality of roll stands of a mandrel mill as a retentive force value every time when it passes through each roll stand of the mandrel mill, and it is calculated from the drive torque of the motor. A calculation unit that calculates a retentive force value from the torque calculation value and the acceleration / deceleration torque of the drive mechanical system, and an immediately preceding biting detection unit that detects the timing immediately before the rolling material is bitten into the first roll stand of the mandrel mill, when the signal immediately before biting of the bite immediately before detecting unit is output, bite the Ritendo force values stored stores the Ritendo force value calculated by the calculation section as a torque component of the machine loss in A lock-on calculation unit that calculates the immediately preceding retentive force value, a retentive force value that is output from the calculation unit, and an immediately preceding bite retention that is output from the lock-on calculation unit. It is obtained by a rolling Ritendo force calculator for calculating a rolling Ritendo force value from a force value.

The retentive force value calculated by the calculation unit is obtained by removing the acceleration / deceleration torque component from the torque calculation value of the motor applied each time the rolling material passes through each roll stand, and calculating the torque and mechanical loss component for rolling. Tei has a torque Ru.
The retentive force value is continuously calculated at any time, and is output to the rolling retentive force calculation unit and the lock-on calculation unit.

In the lock-on calculation unit, a signal immediately before the rolling material is bitten into the first roll stand of the mandrel mill is input from the bite detection unit. Then, the lock-on calculation unit stores the above-mentioned retentive force value when the signal immediately before the biting is input. The lock-on calculation unit uses the stored retained force value as the torque component for the mechanical loss.
And to calculate the clipping position immediately before Ritendo force value, and outputs to the rolling Ritendo force calculating section.

The rolling retentive force calculation unit calculates a rolling retentive force value from the retentive force value continuously output at any time and the retentive force value immediately before biting. That is, in the rolling retentive force calculation unit, since the torque for mechanical loss is included in the retentive force value continuously output at any time, the torque for rolling is removed from this retentive force value, that is, the mechanical loss component. By removing the torque value just before biting, which is the torque, from the retentive force value, the true torque of the motor that acts only on rolling can be obtained as the rolling retentive force value.

Therefore, this rolling retentive force value is a value obtained by removing the constant retentive force value immediately before biting from the retentive force value that is continuously and variably calculated at any time. Instead, it is possible to obtain a detailed and appropriate rolling situation.

Further, the rolling anomaly detecting device of the present invention compares the above-mentioned retentive force computing device with the rolling retentive force value computed by this retentive force computing device and the preset allowable range of the rolling retentive force value. The comparison unit and the determination unit that determines the quality of the rolled state based on the comparison result by the comparison unit are provided.

In the above structure, the rolling abnormality detecting device is
The comparison unit compares the rolling retentive force value calculated by the retentive force calculation device with the set allowable range, and when the rolling retentive force value exceeds the allowable range, the judging unit judges that the rolling is abnormal and cancels rolling. To do. By doing so, it is possible to grasp in detail the motor behavior each time the rolled material passes through the roll stand in detail, and thus when a rolling abnormality occurs, it can be immediately detected.

Further, in the rolling abnormality detecting device of the present invention, in the above-mentioned structure, the allowable range of the rolling retentive force value in the comparison section is a constant ratio with respect to the rolling retentive force value when passing through each roll stand. It is provided. By doing so, it becomes possible to detect which roll stand the abnormal rolling occurs at.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the retentive force computing device and rolling abnormality detecting device of the present invention will be described below with reference to FIGS. FIG. 1 shows a schematic configuration of a rolling anomaly detecting device equipped with a retentive force computing device of the present invention. FIG. 2 shows displacement states of the rotation speed and the torque current value of the drive motor of the mandrel bar in the rolling process in the mandrel mill. FIG. 3 shows the state of displacement of the torque current value in the retention force calculation device and rolling abnormality detection device of the present invention.

In FIG. 1, S is a mandrel mill, P is a hollow shell as a rolled material, B is a mandrel bar, and 1 is a mandrel mill S equipped with equipment for holding the mandrel bar B, for example. It is a rolling abnormality detecting device equipped with the retentive force calculating device 11, which is configured as follows.

Reference numeral 2 denotes a bar retainer that holds the hollow shell P having the mandrel bar B inserted therein and conveys it to the mandrel mill S. This bar retainer 2 is a bar retainer drive motor 2A and a speed reducer 2B which are drive sources, and a bar retainer. Drive wheel 2 that is rotated by the drive force of drive motor 2A
C, a driven wheel 2D provided at a position separated from the drive wheel 2C by a predetermined distance, and a chain 2E hung across the drive wheel 2C and the driven wheel 2D,
A latch 2F attached to the chain 2E and holding the mandrel bar B is provided.

Reference numeral 3 denotes a bar retainer drive device which is a variable speed power supply device for the bar retainer drive motor 2A of the bar retainer 2.
Performs speed control of the retainer drive motor 2A according to a preset speed program, and outputs a torque calculation value T1 when the retainer drive motor 2A is driven to a retention force calculation device 11 described later.

Reference numeral 4 is a comparison section for comparing a rolling retentive force value F output from a later-described retentive force computing device 11 with a preset allowable value. Reference numeral 5 is a determination unit that determines whether there is a rolling abnormality based on the comparison result output from the comparison unit 4.

The retentive force calculating device 11 mounted on the rolling abnormality detecting device 1 having the above-mentioned structure is constructed as follows.

Numeral 11A indicates the inertia torque (hereinafter referred to as acceleration / deceleration torque Ta) associated with the acceleration / deceleration of the retainer drive motor 2A from the calculated torque value T1 output from the retainer drive device 3 as shown in the following formula 1. The first to calculate the load torque T by subtracting and removing the acceleration / deceleration torque Ta
It is a calculation unit.

[0026]

## EQU1 ## T = T1-Ta However, T: load torque T1: Torque calculation value Ta: Acceleration / deceleration torque

The load torque T calculated by the first calculation unit 11A, when output from the first calculation unit 11A, is equal to the torque TL for rolling and the torque TB corresponding to the mechanical loss.
Since it includes, it can be expressed as the following Expression 2.

[0028]

[Equation 2] T = TL + TB However, TL: Torque for rolling TB: Torque for mechanical loss

11B uses the load torque T calculated by the first calculation unit 11A as shown in the following formula 3 to reduce the speed of the reduction gear 2
The torque applied to the bar retainer drive motor 2A when the rolled material passes through each roll stand of the mandrel mill S is multiplied by a constant obtained from the ratio of the unique reduction gear ratio of B and the radius of the drive wheel 2C. It is a second calculation unit that calculates as the retention force value F1. The retentive force value F1 calculated by the second calculating unit 11B is output to the lock-on calculating unit 11D and the rolling retentive force calculating unit 11E described later.

[0030]

[Formula 3] F1 = T × (i / R) However, F1: Retention force value i: Reduction gear ratio R: Drive wheel radius

The retentive force value F1 can also be expressed by the following expression 4 based on the above expression 2.

[0032]

[Equation 4] F1 = (TL + TB) × (i / R)

Reference numeral 11C is an immediately preceding biting detecting section for detecting the timing immediately before the rolled material is bitten into the first roll stand of the mandrel mill S, and the signal immediately before the biting is a lock-on calculation section 11D which will be described later. Is output to.

11D, the second operation unit 1 when the signal immediately before the biting from the immediately before biting detection unit 11C is input.
Stores the Ritendo force value F1 input from 1B, as shown in Equation 5 below, calculates the clipping position immediately before Ritendo force value F0 the stored said Ritendo force value F1 as a torque component of the machine loss in The rolling retention force calculation unit 1 described later
It is a lock-on calculation unit that outputs to 1E.

[0035]

[Formula 5] F0 = TB × (i / R) * TL = 0 However, F0: Retentive force value immediately before biting

11E is a mandrel based on the retentive force value F1 output from the second computing unit 11B and the immediately preceding retentive force value F0 output from the lock-on computing unit 11D, as shown in the following equation 6. It is a rolling retentive force calculation unit that calculates the true torque applied to the bar retainer drive motor 2A as the rolling retentive force value F each time it passes through each roll stand in the mill S. This rolling retention force calculation unit 11
The rolling retention force value F from E is output to the comparison unit 4 of the rolling abnormality detection device 1.

[0037]

## EQU6 ## F = F1-F0 However, F: rolling retention force value

The rolling retention force value F is the acceleration / deceleration torque Ta.
This is a value obtained by removing elements that vary regardless of rolling, such as torque TB for mechanical loss, that is, a bar retainer drive motor 2A that is provided when rolling material passes (rolls) through each roll stand. Is the torque. In addition,
The rolling retention force value F can also be expressed by modifying Equation 1 to Equation 4 described above and modifying Equation 7 below.

[0039]

[Equation 7] F = {(T-TB) × i} / R = TL × (i / R)

Next, the retentive force calculation device 11 having the above configuration
The rolling abnormality detection operation of the rolling abnormality detection device 1 equipped with will be described.

A mandrel bar B is axially penetrated through the hollow shell P. The rear end of the mandrel bar B is attached to the latch 2F, and the drive wheel 2C is driven by the bar retainer drive motor 2A via the speed reducer 2B to move the latch 2F on the chain 2E in the driven wheel 2D direction. , The mandrel bar B moves. Then, the mandrel bar B is moved to penetrate the hollow shell P, and the hollow shell P in this state is inserted into the mandrel mill S.

The retainer drive motor 2A is driven by the retainer drive device 3 based on a predetermined speed program so as to coincide with this speed program. Changes in general rotation speed and torque current value of the bar retainer drive motor 2A when rolling by the mandrel mill S are as shown in FIGS.

As shown in FIG. 2A, the time A until the hollow shell P is caught in the first roll stand of the mandrel mill S and the hollow shell P passes through the final roll stand of the mandrel mill S. The time C after the completion of rolling is to increase the rotation speed and change the drive torque. At time B during rolling, the rotation speed and torque are kept constant.

Here, the torque of the bar retainer drive motor 2A is shown in FIG. 3 by the calculation result of the retention force calculation device 11 of the present invention. In the region of time A and time C, the behavior of FIG. 2 (b) and the behavior of FIG. 3 are similar to each other,
Since the hollow shell P does not pass through the roll stand, that is, the retention force value F0 just before biting does not act,
This is because the behavior of the retention force value F1 continuously calculated and output from the rolling retention force calculation unit 11E is reflected as it is.

Therefore, in the time B region where the hollow shell P passing through the mandrel mill S has a constant speed, the hollow shell P is
Passes through multiple roll stands from the entrance side,
According to the calculation result of the retentive force calculation device 11 of the present invention shown in FIG. 3, during normal rolling, as shown by the solid line in FIG.
Until the tip of the hollow shell P passes through the final roll stand of the mandrel mill S, the hollow shell P remains in the mandrel mill S.
Since it is drawn from the entrance side to the exit side of the
Until the tail end of the hollow shell P passes through the final roll stand of the mandrel mill S, the behavior gradually increases.

That is, for example, immediately before the hollow shell P is caught in the first roll stand, the lock-on calculation unit 11D is used.
Retaining force value F0 immediately before biting is output from the hollow shell P
When is bitten into the first roll stand, the retend force value F0 immediately before biting is subtracted from the rolling retend force value F, so the rolling retend force value F becomes smaller than the retend force value F1 calculated up to that point. , A descending line as shown in FIG.

Then, for example, from the time when the hollow shell P is bitten into the first roll stand to the time when it advances to the next roll stand, unless the rolling abnormality occurs, the rolling retentive force value F (F1-F0). Is almost constant, and therefore is substantially flat as shown in FIG. Such behavior is repeated each time the roll stand is passed.

In the abnormal rolling detection device 1, the comparison unit 4 is shown in FIG.
As shown by the alternate long and short dash line, an allowable value is provided for the rolling retentive force value F, and this allowable value is provided at a constant ratio with respect to the rolling retentive force value calculated when passing each roll stand, for example. The rolling condition is monitored.

Here, the hollow shell P is partially compressed between certain roll stands to form a wrinkle, and an excessive rolling reaction force is generated in the hollow shell P passing through the roll stand. When abnormal rolling occurs such that thin wall rolling tear due to excessive tension occurs and the hollow shell P is not drawn into the exit side of the mandrel mill S, in any case, as shown by the broken line in FIG. The retentive force value F sharply increases.

When the comparison unit 4 determines that the rolling abnormality has occurred and the rolling retention force value F exceeds the allowable value shown by the alternate long and short dash line in FIG. 3, it outputs a signal to that effect to the determination unit 5. . When a signal indicating that the rolling retention force value F exceeds the allowable value is input, the determination unit 5 determines that a rolling abnormality has occurred and immediately controls the equipment to stop.

In this way, the retentive force computing device 11 is
From the driving torque and acceleration / deceleration torque of the bar retainer drive motor 2A, and the torque immediately before rolling that is not used for rolling, the true value for rolling that varies each time the hollow shell P passes through the roll stand of the mandrel mill S. Since the torque of is calculated as the rolling retention force value F, the rolling behavior can be grasped reliably and in detail.

Then, the above-mentioned retention force calculation device 11
Since the rolling abnormality can be detected reliably and early by installing the rolling abnormality in the rolling abnormality detection device 1, it is possible to judge whether the equipment is stopped or not in the initial stage when the rolling abnormality occurs. As a result, it is possible to prevent the equipment in the mandrel mill S from being damaged, and it is possible to prevent the trouble that occurs in the hollow shell P, and to minimize damage and loss of downtime.

Further, the rolling anomaly detecting device 1 includes a hollow shell P
Since the rolling retentive force value F fluctuates every time the rolling stand passes through the roll stand, if it is provided at a constant ratio with respect to the rolling retentive force value when passing through each roll stand, it may occur when the rolling stand passes through. The decision can be made and the treatment can be promptly performed.

In addition to the above, the allowable value may be set as an average value of a certain ratio in the regenerating direction in accordance with the behavior of the actual rolling retention force value F. In this case, which roll is used. Although it is not possible to detect whether a rolling abnormality has occurred at the time of passing through the stand, it is possible to detect a rolling abnormality much faster and more accurately than before.

[0055]

As described above, in the retentive force computing device of the present invention, the computing unit constantly computes the retentive force value of the motor, and the signal immediately before the rolled material is bitten into each roll stand is input. The retentive force value at that time is stored, and the stored retentive force value is used as the torque for the mechanical loss.
And was then calculates and outputs bite immediately before Ritendo force value. Thus calculates the rolling Ritendo force value and a Ritendo force value and the bite immediately before Ritendo force values calculated at all times, through each roll stand At this time, the true torque of the motor can be monitored as a rolling retentive force value to grasp the behavior of the motor in detail and appropriately.

Further, the rolling anomaly detection device of the present invention includes a retentive force calculation device of the present invention, and a comparison unit that compares the rolling retentive force value calculated by the retentive force calculation device with a preset allowable value. since a determination unit for detecting the rolling abnormality on the basis of the determination of the comparison unit, it is possible to detect reliably, yet early abnormality rolling each of rolling in each roll stand, therefore, the rolling abnormality occurs Not only can damage to equipment caused by doing so be minimized, but loss of downtime such as a stop due to the generation of tear material can be suppressed to a minimum.

Further, in the rolling abnormality detecting device of the present invention, the allowable range provided for the rolling retentive force value in the comparison section is set at a constant ratio with respect to the rolling retentive force value when passing through each roll stand. It is possible to detect which roll stand the rolling abnormality has occurred, and it is possible to promptly take action when the rolling abnormality occurs.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a rolling abnormality detecting device of the present invention equipped with a retentive force calculating device of the present invention.

FIG. 2A is a diagram showing a displacement of a rotation speed of a motor driving a mandrel bar, and FIG. 2B is a diagram showing a displacement of torque of a motor driving the mandrel bar.

FIG. 3 is a diagram for explaining a setting situation of an allowable value and a rolling abnormality detection situation in the rolling force calculation device of the present invention and the rolling abnormality detection device of the present invention.

FIG. 4 is a diagram for explaining a conventional method for detecting rolling abnormality from a torque current value of a motor for driving a mandrel bar.

[Explanation of symbols]

1 Rolling anomaly detector 2 bar retainer 2A bar retainer drive motor 2B reducer 2C drive wheel 3 Retainer drive device 4 comparison section 5 Judgment section 11 Retention force calculation device 11A First calculation unit (calculation unit) 11B Second operation unit (operation unit) 11C Immediately before bite detector 11D Lock-on calculation unit 11E Rolling retention force calculation unit B Mandrel bar S Mandrel Mill P Hollow shell

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI B21B 37/78 B21B 37/00 128B B21C 51/00 (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 17 / 02 B21B 33/00 B21B 35/00 B21B 37/00 B21B 37/48 B21B 37/78 B21C 51/00

Claims (3)

(57) [Claims] 1. A retentive force calculation device for calculating a torque of a motor for feeding a rolled material to a plurality of roll stands of a mandrel mill as a retentive force value every time when the roll stands of the mandrel mill are passed. Calculation unit that calculates the retentive force value from the torque calculation value calculated from the driving torque of the drive machine and the acceleration / deceleration torque of the drive machine system, and the meshing unit that detects the timing immediately before the rolling material is meshed with the first roll stand of the mandrel mill. The just before-engagement detection unit, and when the just before-be-engaged signal is output from the just-before-engagement detection unit, the retentive force value calculated by the arithmetic unit is stored and the stored retentive force value is equivalent to the mechanical loss. wherein the lock-on calculating unit for calculating a clipping position immediately before Ritendo force value as a torque component, Ritendo force value outputted from the arithmetic unit lock-on operation unit And a rolling retentive force calculation unit that calculates a rolling retentive force value from the immediately preceding biting retend force value output from the retentive force calculation device. 2. A retentive force calculation device according to claim 1,
A comparison unit that compares the rolling retentive force value calculated by this retentive force calculation device with a preset allowable range of the rolling retentive force value, and based on the comparison result by this comparing unit, determine whether the rolling state is good or bad. And a rolling abnormality detecting device. 3. The rolling abnormality detection according to claim 2, wherein the allowable range of the rolling retentive force value is set at a constant ratio with respect to the rolling retentive force value when passing through each roll stand in the comparison section. apparatus.