JPH079550U - Bulging detection device for continuously cast slabs - Google Patents

Abstract

(57) [Summary] [Purpose] During continuous casting, hot spots from the complete freezing point of the slab to the cutting machine are used to detect shape defects such as bulging and warpage, and early detection of defective products and slab cutting. Prevent damage to equipment such as machines. [Structure] A photoelectric sensor 1 including a light projector 2 and a light receiver 3 is installed between a pinch roll 14 and a slab cutting machine 15 of a continuous casting facility. The light emitter 2 and the light receiver 3 are arranged so that the amount of light received changes depending on the shape in the thickness direction of the slab, and the controller 4 calculates the amount of light received by the light receiver 3 to obtain the amount of slab thickness. When exceeds the reference value, an abnormal signal is output. When the slab thickness exceeds the reference value due to deformation such as bulging or warpage of the slab, an abnormality alarm or a strand stop command is output.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a device for detecting a defective shape due to bulging of a slab or warpage of the slab in the thickness direction of a continuously cast slab.

[0002]

[Prior art]

 As shown in FIG. 2, the continuous casting equipment comprises a ladle 10, a tundish 11, a mold 12, a support roll group (roller apron) 13, a pinch roll 14, a traveling type slab cutting machine 15, etc. The cast slab S in which the solidified shell is formed in the mold 12 is guided and supported by the roller apron 13 and cooled with spray water or the like, straightened by the pinch roll 14 and drawn out, and cut into a predetermined length by the slab cutting machine 15. is doing.

In such continuous casting equipment, in the cast slab S, bulging occurs in which the solidified shell swells between the slab supporting rolls due to the static pressure of molten steel, and when this bulging occurs, internal cracks and vertical cracks occur inside the cast slab. Cracks and the like occur and deteriorate the quality of the slab. For this reason, in the past, contact type or non-contact type measuring instruments were installed between the slab support rolls to measure the bulging of the slab.

As a contact type bulging measuring device, a touch roller (or a wheel) is pressed against a slab between slab supporting rolls by an air cylinder, and the slab shape is measured by a displacement meter mounted on the same axis as the cylinder rod. Some are measured (Japanese Utility Model Laid-Open No. 62-86952).

On the other hand, the non-contact type bulging measuring device includes a means for detecting the displacement of a pair of slab support rolls and an ultrasonic range finder for detecting the displacement of the slab between the slab support rolls. There is one that measures bulging from the displacement of a cast piece and the displacement of a roll (Japanese Patent Laid-Open No. 61-67550).

[0006]

[Problems to be solved by the device]

 However, recently, due to the increase in casting speed, not only bulging between rolls but sometimes bulging also occurs in the latter stage of the pinch roll, where there is no pressing force by the rolls, and this bulging becomes large. May damage the slab cutting machine. Further, the slab cutting machine may be damaged due to deformation such as warpage of the slab.

When measuring bulging from the latter stage of such a pinch roll to the front of the slab cutting machine, the conventional bulging measuring device is complicated and costly, and the maintenance labor is large. There's a problem.

The present invention has been made to solve the above-mentioned problems, and an object thereof is a device having a relatively simple structure, which is used for hot casting from a position of complete solidification of a cast piece to a cutting machine. An object of the present invention is to provide a bulging detection device capable of detecting a defective shape such as bulging or warpage of one piece, and preventing a defective product from being detected early and preventing equipment damage such as a slab cutting machine.

[0009]

[Means for Solving the Problems]

 This invention is an apparatus for detecting bulging of a continuously cast slab in a continuous casting facility equipped with a mold, a support roll group, a pinch roll, and a slab cutter, and is installed between the pinch roll and the slab cutter. The light emitter and the light receiver are arranged to face each other across the slab in the width direction of the slab, and the photoelectric sensor is arranged so that the light reception amount changes depending on the shape in the thickness direction of the slab, and the light reception amount of the light receiver. Is calculated to obtain the cast slab thickness amount, and when the cast slab thickness amount exceeds a reference value, a controller that outputs an abnormal signal (alarm or CC strand stop command) is configured.

[0010]

[Action]

 In the above configuration, a part of the luminous flux projected from the projector of the photoelectric sensor is blocked by the cast piece and enters the photoreceiver, and the controller calculates the cast piece thickness based on the amount of light received by the photoreceiver. It When the thickness of the slab exceeds the set standard value, an abnormal alarm is output and a defective shape such as bulging or warpage of the slab is detected.

[0011]

【Example】

 Hereinafter, the present invention will be described in detail with reference to an illustrated embodiment. As shown in FIGS. 1 and 3, a photoelectric sensor 1 including a light projector 2 and a light receiver 3 is installed between a pinch roll 14 and a traveling type slab cutting machine 15. The light projector 2 and the light receiver 3 are arranged so as to face each other across the slab S in the width direction of the slab.

The photoelectric sensor 1 uses a so-called optical wide sensor having a wide detection area and a parallel light flux L in the vertical direction. The lower portion of the parallel light flux L is irradiated to the upper portion in the thickness direction of the slab S, and Even if the slab size (thickness) is changed, the upper end of the parallel light flux L is positioned at a sufficient distance from the upper surface of the slab S. The light receiver 3 has a large number of light receiving elements scanned by the controller 4, and a detection signal proportional to the amount of light received can be obtained.

As shown in FIG. 4A, the controller 4 arithmetically processes the received light amount detection signal from the light receiver 3 to calculate the cast piece thickness, deviation, etc., and displays the calculated value as a measured value. Further, a set value (reference value) can be set, and as described later, this set value is compared with the calculated cast piece thickness, and the result is output to the analog output device 5 and the relay output device 6.

The analog output device 5 and the relay output device 6 are connected to the control device of the CC machine, issue an abnormal alarm, and stop the CC machine etc. by the CC strand stop command.

FIG. 4B shows the light amount L _{1 of} the parallel light flux L projected from the light projector 2 which is blocked by the cast slab S and the light amount L ₂ which is incident on the light receiver 3. The lowest point position of the light amount L ₂ incident on the light receiver 3 can be arbitrarily set as a reference value (ingot thickness) T ₀ within the range of the parallel light flux L, and below this reference value T _0. By resetting to 0, if no defective shape of the slab occurs during normal operation, no output is sent from the controller 4.

Once the shape defect of the cast piece occurs, the light quantity L ₂ incident on the light receiver 3 decreases, and when the cast piece thickness exceeds the set reference value T ₀ , an alarm signal or the like is issued. This reference value T ₀ is preset according to the slab size (thickness). For example, in the case of a slab thickness of 300 mm, it is set to 320 mm (added by 5 to 10%).

The above-described configuration operates as follows.

(1) As shown in FIG. 5, when the shape of the slab S is normal, the slab thickness calculated from the amount of received light incident on the light receiver 3 must exceed a preset reference value. There is no signal, and no signal is output because it is reset to 0.

(2) When the cast slab S undergoes bulging (see FIG. 6 (a)) or deformation such as warpage (see FIG. 6 (b)), the amount of light received by the light receiver 3 changes, The controller 4 performs arithmetic processing to display the cast slab thickness amount and deviation amount.

(3) When the thickness of the cast slab S becomes large and exceeds the reference value, an abnormal alarm is issued and a CC strand stop command is output. As a result, the CC machine is stopped, the casting of the strand is interrupted, and damage to the cutting torch of the slab cutting machine 15 or the like is prevented in advance.

[0021]

[Effect of device]

 As described above, the bulging detection device according to the present invention has a photoelectric sensor consisting of a projector and a light receiver installed between the pinch roll and the slab cutting machine, and detects the slab thickness by detecting the change in the amount of received light. When the thickness exceeds the set value, an alarm is issued to detect abnormalities in shape, such as bulging and warpage of the slab, during the heat from the complete freezing point of the slab to the cutting machine. It is possible to prevent it from being discovered in advance or damage to equipment such as a slab cutting machine.

Further, it is installed in the equipment after the pinch roll (slab straightening device), and is excellent in detection accuracy and durability without being affected by spray water, steam, and radiant heat of the slab.

Further, since it is a non-contact type by an optical system and the mechanism is simple, there is an advantage that it is inexpensive and requires little maintenance labor.

[Brief description of drawings]

FIG. 1 is a perspective view showing a bulging detection device according to the present invention.

FIG. 2 is a schematic side view showing a continuous casting facility.

FIG. 3 is a transverse cross-sectional view of a strand showing an installed state of a photoelectric sensor.

FIG. 4 (a) is a schematic diagram showing an overall configuration of a bulging detection device, and FIG. 4 (b) is an explanatory diagram showing a light blocking state of a parallel light flux.

FIG. 5 is a perspective view showing a detection state when the shape of a cast piece is normal.

FIG. 6A is a perspective view showing a detection state when bulging occurs in the slab, and FIG. 6B is a perspective view showing a detection state when warping occurs in the slab.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoelectric sensor 2 Emitter 3 Light receiver 4 Controller 5 Analog output device 6 Relay circuit device 10 Ladle 11 Tundish 12 Mold 13 Support roll group 14 Pinch roll 15 Slab cutting machine

Claims (1)

[Scope of utility model registration request] 1. An apparatus for detecting bulging of a continuously cast slab in a continuous casting facility equipped with a mold, a support roll group, a pinch roll, and a slab cutting machine, which is installed between the pinch roll and the slab cutting machine. The light emitter and the light receiver are arranged to face each other across the slab in the width direction of the slab, and the photoelectric sensor is arranged so that the light reception amount changes depending on the shape in the thickness direction of the slab, and the light reception amount of the light receiver. Is calculated to obtain the slab thickness amount,
A bulging detection device for continuously cast slabs, comprising a controller that outputs a signal in the event of an abnormality when the slab thickness exceeds a reference value.