JP3347932B2 - Automatic slab stop method and automatic stop control 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 method for loading a slab into a heating furnace of a hot rolling mill, wherein the slab conveyed on a carry-in table at a heating furnace entrance is positioned at an optimum position according to its length. The present invention relates to a slab automatic stop method and an automatic stop control device for automatically stopping a slab.

[0002]

2. Description of the Related Art As a heating furnace of a hot rolling mill, a continuous heating furnace is generally used. As shown in FIG. 3, a slab S carried in by a roller table 2 is heated by a pusher or the like in a posture as it is. The slab S is charged into the furnace from the charging port 1 and heated to a predetermined temperature while being sequentially and continuously conveyed by the conveying device in the furnace. A walking beam system or a skid rail pusher system is employed as a slab transfer device in a furnace. The walking beam type conveying device 5 is composed of a fixed skid 6 and a moving skid 7, and by moving the moving beam 7 in a rectangular shape in a side view, the slab S is continuously transferred while being alternately supported by the fixed skid and the moving skid. I have.

In such a continuous heating furnace, the slabs of various lengths are evenly loaded on the in-furnace transfer device,
It is necessary to ensure stability, and it is important to stop slabs of various lengths at predetermined optimum positions on the roller table on the side of the heating furnace inlet. A pair of moving skids 7 of the in-furnace transfer device are usually arranged in parallel in the furnace, and the way of placing slabs on these two units is changed according to the slab length (see FIG. 3). The target stop position of the slab S in FIG.

Conventionally, a speed detector such as a pulse generator is provided on the roll of the roller table 2, the amount of movement of the slab from the detection of the slab tip position is measured by the speed detector, and the slab tip is stopped at a predetermined stop by a sequencer. Automatic position control was performed to stop at the target position. The length of the slab S is determined by using the dimension obtained in the previous step or by the amount of movement during detection of the leading and trailing ends of the slab, and the stop target position is set from the slab length.

[0005]

However, in the conventional slab position detection method, the position of the slab on the roller table cannot be accurately grasped due to slippage between the slab and the roll, and the slab is not allowed to have its length. It was not possible to accurately and automatically stop at the corresponding optimal stop target position. For this reason, after the slab is stopped by the automatic position control, it is necessary to adjust and confirm the inching position visually by an operator, and thus there is a problem that the heating furnace charging operation cannot be performed quickly and human labor is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to accurately and automatically transfer slabs of various lengths to various optimum stop target positions over a wide range of a transfer table stop zone. An object of the present invention is to provide an automatic stop method and an automatic stop control device that can be stopped.

[0007]

To achieve the above object, a method for automatically stopping a slab according to the present invention automatically stops a slab conveyed on a transfer table at an optimum position corresponding to the slab length. When detecting the slab tip at the entrance detection point of the stop zone on the transport table,
Start measuring the distance x from the reference point 0 to the tip of the slab,
It said slab length distance x _S from the reference point 0 to measure a distance x ₁ to the slab tip calculate the slab length L, a from the reference point 0 to the optimum stop position upon detection of the slab rear end in the inlet detection point is calculated from L, drives and controls the conveying table as the optimum stop position distance x _S coincides with the measurement distance x.

An automatic stop control device according to the present invention is an automatic stop control device for a slab for automatically stopping a slab conveyed on a transfer table at an optimum position corresponding to the slab length. A detection sensor (e.g., a photoelectric switch) that is installed at the entrance of the zone and detects the passage of the front and rear ends of the slab, and is installed at the end of the stop zone and measures the distance x from the reference point 0 to the front end of the slab. a distance meter sensor (such as a laser rangefinder) from measurement distance x ₁ of the rangefinder sensors when detecting the slab rear end by the detection sensor to calculate the slab length L, a from the reference point 0 to the optimum stop position obtains distances x _S from the slab length L, a consist and processing control means for driving and controlling the conveying table from a distance x _S to the measuring distance x and the optimum stop position. In addition, a side guide for correcting the position of the skew slab is provided at the entrance side of the detection sensor in the transport table.

In the above configuration, the slab length L
From measured distances x ₁ at a known distance A slab rear end detection from the reference point 0 to the entrance detection point given by L = A-x _1. Calculation formula of the distance x _S of the optimum stop position with respect to the various slub length L has been previously registered, the distance x _S of the various optimum stop position corresponding to the slub length L by the calculation formula is calculated, this distance x _S and distance x of distance sensor
As a result, automatic stop control is performed so that the tip of the slab is accurately located at the optimum stop position.

Since the slab tip position is directly measured by the range finder sensor, a measurement error does not occur due to a slip between the slab and the roll as in the prior art, and the slab length and the optimum stop target position can be accurately calculated. In addition, the slab position can be accurately grasped, and slabs of various lengths can be automatically and accurately stopped at the optimal stop target position.
In addition, since the slab tip position is sequentially measured by the range finder sensor, automatic stop control can always be performed so that the slab tip stops at the target stop position. The slab is automatically retracted and the stop position can be corrected. In addition, accurate automatic stop control can be performed by a combination of two sensors, and the object can be achieved with a relatively simple device configuration.

Further, by using the side guide, the slab can be guided on the detection line of the range finder sensor, and the range finder sensor can be installed at a fixed position for slabs of any width. Further, by setting the opening degree of the side guide in accordance with the width of the slab, the inclination of the slab can be reduced, and the measurement error of the slab length can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in the drawings. This is an example in which the present invention is applied to a loading-side roller table of a walking beam type continuous heating furnace, and FIG. 1 shows an example of a device configuration of an automatic slab stop control device according to the present invention. FIG. 2 shows a flowchart of a method for automatically stopping a slab according to the present invention.

In FIG. 1, a roller conveyor 2 for carrying in a slab is arranged on the loading side of the heating furnace 1 so as to be orthogonal to the core CL, and the end portion thereof extends toward the loading port. ing. A stopper 3 is provided at the end position of the roller conveyor 2, and a furnace wall position a and a furnace wall position b of the heating furnace 1 are provided.
A stop zone 4 is formed on the roller conveyor 2 defined by the above. In the heating furnace 1, two walking beam type transfer devices 5 each including a fixed skid 6 and a movable skid 7 are provided (see FIG. 3).

In such a roller conveyor 2, a photoelectric sensor 10 for detecting the passage of the leading and trailing ends of the slab S is provided at the entrance side of the stop zone 4, and a laser distance meter 11 is provided outside the stopper 3. The photoelectric sensor 10 uses a transmission type photoelectric switch including a light emitter and a light receiver. The photoelectric sensor 10 has a high-speed response type (response time ≦ 0.
35 msec).

The laser distance meter 11 is a triangulation type distance measuring sensor having a light projecting element, a light projecting lens, a light receiving lens, a position detecting element, and the like, and has a long measuring distance and a wide measuring range. Further, the laser light is applied to the roller conveyor 2.
The roller is set so that it is irradiated in parallel with the transfer center line, and is further eccentrically mounted on the side opposite to the heating furnace than the transfer center of the roller conveyor 2 so that measurement can be performed even on a narrow slab S. Since it is difficult for the laser range finder 11 to detect a short distance, the reference point 0 of the arithmetic processing described later is set to the furnace wall position a of the heating furnace, and the laser range finder 11 is installed at a predetermined distance outward from the furnace wall position a.

The detection signals of the photoelectric sensor 10 and the laser distance meter 11 are processed by the measuring device 12 as described later, and the obtained slab length L and the distance x from the reference point 0 to the tip of the slab are determined by a controller (sequencer). ) 13 is output. In the controller 13, the distance x _S from the reference point 0 corresponding to the slub length L until the optimal stopping position is calculated by the calculation processing described later, the driving motor of the roll 2a of the roller conveyor 2 on the basis of the distance x _S Drive control.

A side guide 14 for correcting the slab position is provided at a predetermined distance from the photoelectric sensor 10 in front of the photoelectric sensor 10. This side guide 14
Is installed on the heating furnace side of the roller conveyor 2 so that the opening can be set by tilting with a hydraulic cylinder or the like, so that the slab S is guided on the optical axis of the laser beam of the laser distance meter 11, The inclination of the row slab S is forcibly corrected by applying the tip of the side guide to the side of the slab.

In the above configuration, automatic stop control of the slab is performed as follows (see the flowchart of FIG. 2).

(1) The opening degree of the side guide 14 is set according to the width of the slab S, and the stop zone 4 is set by the roller conveyor 2.
The position and inclination of the slab S carried into the inside of the slab S are corrected by the side guides 14 so that the laser light of the laser range finder 11 deviated to the non-heating furnace side is irradiated to the tip surface of the slab S.

(2) When the tip of the slab passes through the position of the photoelectric sensor 10, the photoelectric sensor 10 is activated, and the laser distance meter 11 starts to emit a laser beam according to the operation signal. The measuring device 12 sequentially measures the distance x from the reference point 0 to the slab tip.

(3) In the measuring device 12, when the rear end of the slab passes the position of the photoelectric sensor 10, the photoelectric sensor 1
The reference signal 0 at the time of detecting the rear end of the slab
Distance x ₁ to the slab tip is obtained from the distance x ₁
The slab length L is calculated from

The slab length L is obtained by the following equation: L = A-x ₁ (A: distance between reference point 0 and position of photoelectric sensor 10, known).

[0023] (4) controllers in 13 calculates by using a calculation formula to be described later distance x _S from the reference point 0 from the resulting slab length L to the optimum target stop position. At the same time, the transport speed of the roller conveyor 2 is reduced by the controller 13. The distance x measured by the laser distance meter 11 is sequentially input to the controller 13.

(5) The distance x _S to the optimum stop target position is compared with the measured distance x. If x and x _S do not match, the slab is moved forward or backward. The light emission of the total 10 ends.

[0025]

[Numerical example] Specifications of laser rangefinder ・ Measurement distance: 4000 to 14000 mm from front of sensor ・ Measuring range: 10000 mm ・ Measurement cycle: 20 msec (50 times / sec) ・ Measurement accuracy: ± 12 mm / 2σ ・ Emitter: Semiconductor laser ... wavelength 690 nm, maximum output 3
0 mW (Class 3B) ・ Receiver: CCD image sensor, optical filter mounted Photoelectric sensor specifications ・ Detection method: Transmission type ・ Response time: 0.35 msec or less Slab transfer speed: 1.5 m / sec max. Slab temperature: room temperature to 700 ° C In addition, as shown in FIG. 3, there are a large number of stop positions of the slab according to the slab length L, and the optimum stop by the calculation formula shown in Table 1 so that slabs of various lengths are evenly mounted on the left and right. distance x _S of the target position is determined. The stop position is divided into I to V according to the slab length L and the arrangement position in the furnace. In Section III, the slab is transported in the center of the furnace, and in Sections I, II and IV, V, on the roller conveyor 2. It is stopped alternately and transported alternately by the two transporting devices 5.

[0026]

[Table 1]

Slab Position Correction Side Guide The slab S is guided on the optical axis of the laser beam of the laser range finder 11 by the side guide 14, so that the laser range finder 11 is set at a fixed position for slabs of any width. This eliminates the need for a drive mechanism for causing the laser distance meter 11 to follow the slab width direction, and can provide an inexpensive configuration. At the same time, by setting the degree of opening according to the slab width, the slab S
The measurement error due to the inclination of can be reduced. That is, in FIG. 4, the error due to the slab inclination is L−1, and L = l cos θ + y tan θ. However, the slab inclination θ can be reduced for various slab widths, and as shown in Table 2, Error due to slab inclination 0.4% of actual length
It can be:

[0028]

[Table 2]

When the slab was automatically stopped using the stop position target values shown in Table 1 with the above-described side guide, measuring instrument specifications, and slab specifications, the results shown in Tables 3 and 4 were obtained. As shown in Table 3, the slab length L can be measured accurately, and as shown in Table 4, the slab stop position is within a range of ± 50 mm which is a range without practical problems with respect to the target stop position. Could be stopped automatically. The stop accuracy according to the conventional method is ± 100 to 200 mm, and in most cases, the confirmation of the operator and the work of correcting the slab position by inching are required, but the present invention does not require it at all.

[0030]

[Table 3]

[0031]

[Table 4]

If the specifications of the laser distance meter are changed,
It is possible to perform automatic stop control on a table in a longer range than in the present embodiment, and it is possible to cope with a slab of 700 ° C. or more. Further, although the description has been given of the walking beam type continuous heating furnace, it goes without saying that the present invention can be applied to a skid rail / pusher type heating furnace, automatic stop position control of other steel materials, and the like.

[0033]

As described above, according to the present invention, when the tip of the slab is detected by the detection sensor, measurement of the distance x from the reference point 0 to the tip of the slab is started by the distance sensor, and the measured distance at the time of detection of the trailing end of the slab is measured. to calculate the slab length L from x _1,
Obtains distances x _S to the optimum stop position from the slab length L, a for the optimum stop position distance x _S was made to drive control the conveying table to match the measured distance x, the following effects Play.

(1) Since the slab tip position is directly measured by the range finder sensor, there is no measurement error due to slip between the slab and the roll as in the prior art, and the slab length and the optimal stop target position can be accurately determined. The slab position can be calculated, the slab position can be accurately grasped, and slabs of various lengths can be automatically and accurately stopped at the optimum stop target position. In addition, since the slab tip position is sequentially measured by the distance meter sensor, automatic stop control can always be performed so that the slab tip stops at the target stop position. Even if the vehicle goes too far, the slab is automatically retracted and the stop position can be corrected. As described above, the conventional operation of confirming the operator and correcting the slab stop position can be eliminated, which enables quick operation and saves labor.

(2) Accurate automatic stop control can be performed by a combination of two sensors, and a relatively simple device configuration can be achieved.

(3) By using the side guide,
The slab can be guided on the detection line of the range finder sensor, and the range finder sensor can be installed at a fixed position with respect to slabs of any width. Further, by setting the opening degree of the side guide according to the width of the slab, the inclination of the slab can be reduced, and the measurement error of the slab length can be further reduced.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing one embodiment of a device configuration of a slab automatic stop control device according to the present invention.

FIG. 2 is a flowchart of a method for automatically stopping a slab according to the present invention.

FIG. 3 is a schematic plan view showing stop positions and stop position divisions of slabs of various lengths in a transfer table and a heating furnace.

FIG. 4 is an explanatory diagram showing an error due to a slab inclination.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heating furnace 2 ... Roller conveyor 3 ... Stopper 4 ... Stop zone 5 ... Walking beam type conveyance device 6 ... Fixed skid 7 ... Moving skid 10 ... Photoelectric sensor 11 ... Laser distance meter 12 ... Measuring device 13 ... Controller 14 ... Side guide

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshiki Hoshino 3 Kashima Plant, Kashima City, Ibaraki Pref. Kashima Plant Industries Co., Ltd. (56) References 7-71921 (JP, A) JP 60-57488 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C21D 1/00 C21D 1/00 117 B65G 43/00

Claims (3)

(57) [Claims] When automatically stopping a slab conveyed on a transfer table at an optimum position corresponding to the slab length, when a slab tip is detected at an entrance detection point of a stop zone on the transfer table, the slab is moved from a reference point 0 to a reference point. starts measuring the distance x to the slab tip, to calculate the slab length L from the measurement distance x ₁ from the reference point 0 to the slab tip when it detects a slab rear end in the inlet detection point from the reference point 0 the distance x _S to the optimum stop position determined from said slab length L, a automatic stop method for slabs the optimum stop position distance x _S, characterized in that the drive control of the conveying table to match the measured distance x . 2. A slab automatic stop control device for automatically stopping a slab conveyed on a transfer table at an optimum position according to a slab length, the slab being installed at an entrance of a stop zone in the transfer table, A detection sensor for detecting the passage of the front end / rear end, a rangefinder sensor installed at the end of the stop zone, for measuring a distance x from a reference point 0 to the front end of the slab, and a rear end of the slab with the detection sensor. from the measured distance x ₁ of the rangefinder sensor upon detection to calculate the slab length L, a
Calculated from the reference point 0 the distance from to the optimum stop position x _S said slab length L, and that an arithmetic processing control means for driving and controlling the conveying table from a distance x _S to the measuring distance x and the optimum stop position An automatic stop control device for a slab. 3. The slab automatic stop control device according to claim 2, wherein a side guide for correcting the position of the skewed slab is provided on the entrance side of the detection sensor in the transfer table. Automatic stop control device.