JPH07100176B2 - How to detect flaw-causing rolls - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when a flaw is generated on the surface of a steel sheet in a pressurizing section of the steel sheet in an electroplating apparatus, a rolling apparatus or the like, quickly and reliably removes the roll causing the flaw. Regarding how to identify.

[0002]

2. Description of the Related Art A conventional method for detecting flaws on the surface of a steel sheet caused by these rolls in a pressure section by rolls is disclosed in, for example, Japanese Patent Laid-Open No. Sho 56-80321 (first conventional method). There is an example), and this method is to detect the occurrence of defects caused by the roll by paying attention to the periodicity of the defects formed by the roll.

Further, as a conventional method for identifying the causal roll that has caused the flaw, for example, Japanese Patent Laid-Open No. 52-9 is used.
Method disclosed in Japanese Patent No. 3385 (second conventional example)
However, this method also pays attention to the periodicity of flaws, and identifies the causal roll from the flaw interval in consideration of each roll diameter and the elongation rate by pressurization.

[0004]

However, the method of the first conventional example is a method of simply judging whether or not the flaw formed on the surface of the steel sheet is formed by a roll. When a plurality of rolls are continuously arranged in the section, it is not possible to specify which roll caused the flaw. Further, according to the method of the second conventional example, although the causal roll can be specified, since a minute expansion rate is used as a parameter (variable) in the calculation, an error is large, especially when the diameters of the rolls are the same. There is a problem in that the change in the flaw interval is poor and it is difficult to identify the cause roll.

Furthermore, in these conventional examples, a considerably long section must be wasted as a detection section without being able to identify the causal roll in order to measure the periodicity of flaws, resulting in a poor yield. Also occurs. Therefore,
The present invention proposes a method for detecting a defect-causing roll that can be performed quickly and reliably in identifying a causative roll that has caused a defect, in which a section of poor quality is short. With the goal.

[0006]

SUMMARY OF THE INVENTION According to the present invention, when a steel sheet passing through a pressure section is flawed, one section of the steel sheet corresponds to each roll of the pressure section in a one-to-one correspondence and at least one of the rolls. A specific section having the same length as the circumference was formed, and when these specific sections of the steel sheet passed through the corresponding rolls, respectively, the rolls were not opened and pressure was applied, and no flaw was generated. The above problem has been solved by proposing a method for detecting a defect-causing roll that detects a specific section and specifies a roll corresponding to this specific section as a defect-causing roll.

[0007]

[Operation] When a steel plate is flawed, a specific section is set in one section of the steel sheet, and the rolls other than the corresponding rolls apply pressure to each specific section (for example,
When there are first to third rolls and the second roll corresponds to the second specific section, the second specific section is pressed by the first and third rolls).

Therefore, since the flaw does not occur in the specific section corresponding to the causative roll that has caused the flaw, each specific section is inspected, and the causal roll is specified by detecting the specific section in which no flaw has occurred. . At this time, since only a specific section needs to be inspected to detect the defect-causing roll, as compared to the method of identifying the causal roll by examining the periodicity of the defect, the section discarded as poor quality is short, and Detection work is quick and reliable.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the method of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram of a flaw-causing roll identifying means. The continuous electroplating apparatus 1 has a plurality of conductor rolls Ri (i = 1, 2, 3, 3) inside thereof.
...) are continuously arranged, and the device 1 serves as a pressurizing section to pass the steel plate S from the left side to the right side in the drawing. Further, on the exit side of the steel plate S of this device 1,
A confirmation device 3 for the observer W is placed, and a confirmation button 4 for confirming that the flaw has disappeared is attached to the device 3.
Further, a DDC (direct digital control device) 5 is arranged in the vicinity of the continuous electroplating device 1, and this DDC 5 controls opening and closing of each conductor roll Ri, and the same control state is set in the cab 6 The line display device 7 has a structure for displaying.

Next, the operation of each device will be described focusing on the DDC 5. First, if a defect occurs during line operation,
The worker V who performs line control gives an instruction to start the specific work of the causal roll Rc that caused the flaw in the DDC 5 through the control device 7 in the operator's cab 6 (FIG. 1, relationship line). On the other hand, D
DC5 is used for each conductor roll R on an arbitrary section of the steel plate S.
a plurality of specific sections Xi (i =
, 1, 2, 3, ...). Then, the opening and closing of each conductor roll Ri is controlled, and the control is performed so that each conductor roll Ri does not pressurize the corresponding specific section Xi (the relationship line in the same figure).

Here, the length L of the specific section Xi is set so that L = πD + α (1) where D is the diameter of the conductor roll R and α is the adjustment value. That is, each conductor roll Ri makes at least one rotation in each specific section Xi and presses the side surface thereof against the steel plate S.

The monitor W monitors whether or not the defect has disappeared at the point A on the output side of the continuous electroplating apparatus 1, and presses the confirmation button 4 when the part where the defect has disappeared reaches point A. , That information is input to the DDC 5 (relation line). On the other hand, in parallel with this work, the DDC 5 always tracks the passing condition of the steel sheet S from the moving speed of the steel sheet S and the distance between the point A and each conductor roll Ri, and which specific section Xi determines the point A. It detects whether it is passing (relation line). That is, it is possible to determine in which specific section Xi the flaw has disappeared, based on the information on the confirmation button 4 and the information on the passing state of the steel plate S, whereby the DDC 5
Specifies the causal roll Rc and displays it on the CRT of the control device 7 (relation line).

Next, a procedure for forming the above-mentioned specific section Xi will be described with reference to FIG. For simplicity of explanation, the continuous electroplating apparatus will be described as having only three conductor rolls R1 to R3. First, at point A,
When a flaw is found on the steel plate S (Fig. 1 (1)), the DDC 5 immediately opens the first roll R1 (Fig. 1 (2)). Then, this opening is performed by the roll circumference length (πD + α) as described above, and this portion is set as the first specific section X1 (see FIG.
(3)). Next, when the terminating end of the first specific section X1 reaches the second roll R2, the DDC 5 opens the same roll R2 ((4) in the same figure), and similarly the second specific section X of the roll circumference length.
2 is formed ((5) in the same figure).

On the other hand, when the tip of the specific section X1 approaches point A, the watchman W starts checking whether there is a flaw ((6) in the same figure). Then, when the steel plate S advances and the end portion of the second specific section X2 reaches the third roll R3, the DDC 5 similarly opens the roll R2 ((4) in the same figure), and the roll circumferential length becomes Three specific sections X3 are formed ((7) and (8) in the same figure).
In addition, in the defect checking work that was performed in parallel with the setting of the specific section Xi, the end portion of the third specific section X3 is A
The process is repeated until the point is passed ((9) in the same figure). It should be noted that when a flaw is detected (FIG. 2 (1)), the first roll R1 to point A becomes a defective section L, and the total of this distance L and a section (3 (πD + α)) used for continuous detection is It is a disposal section that cannot be used as a product.

Here, each roll R1 to R3 has a specific section X.
1 to X3 respectively, and each roll R as described above
i presses the steel plate S while avoiding each corresponding specific section Xi. That is, the first specific section X1 is composed of the second roll R2 and the third roll R3, and the second specific section X2 is composed of the first roll R.
The first and third rolls R3 and R3 further press the third specific section X3 by the first and second rolls R1 and R2. Therefore, when the specific section Xi in which the defect has disappeared is detected, the roll Ri corresponding to this specific section Xi is the causal roll Rc (for example, when the defect has disappeared in the second specific section X2,
The second roll R2 becomes the causal roll Rc), and the causal roll Rc can be easily specified. At this time, the DDC 5 constantly tracks the steel plate S to know which specific section Xi is currently passing through the point A.

Another method of forming the specific section Xi is shown in FIG. First, when a flaw is found on the steel plate S (Fig. 2 (1)), the first roll R1 is opened (Fig. 2 (2)). When the steel plate S moves by πD + α, the first roll R1 is closed and the first specific section X1 is formed here. At the same time, the third roll R3 is opened ((3) in the figure) to form the third specific section X3 ((4) in the figure). Further, the steel plate S advances and the specific section X
When 1 reaches the point A, the flaw detection is started, and when the end of the first specific section X1 reaches the second roll R2, it is released ((5) in the same figure) and the second roll is set here. A specific section X2 is formed ((6) in the same figure). After this, the flaws in the first and second specific sections X1 and X2 are sequentially detected, and a series of work is completed (see FIG.
(7)).

In this forming method, since the third specific section X3 is formed in the defective section L, the discard section having no commercial value can be made shorter. That is,
Depending on the forming method shown in FIG. 2, the discard section is L + 3.
In contrast to (πD + α), depending on the setting method shown in FIG. 3, it becomes L + 2 (πD + α), which is a shorter section.

Depending on the embodiment described above, the DDC5
The steel plate S is tracked using the
Can automatically specify the causal roll Rc that caused the flaw by simply confirming the defect disappearance without paying attention to which specific section Xi is currently passing through the point A. In particular, according to this embodiment, since the plurality of rolls Ri are not simultaneously opened, the plating conditions are not disturbed,
The high quality of the steel plate S can be maintained. It should be noted that in a rolling mill or the like that does not have such constraint conditions, it is possible to open a plurality of rolls at the same time, and by performing such control, it is possible to further shorten the discard section.

Further, when this embodiment is used in an actual line, the discarding section of the steel sheet S required to identify the causal roll is about 100 m, whereas each roll R
The conventional method in which i is opened one by one to check the result is about 3000 m, and it was found that the method of the present example has a great effect in increasing the production efficiency. In this embodiment, the flaw is found by human eyes, but a flaw finding device having an image processing device may be installed instead.

Further, this embodiment is an example in which the present invention is applied to a continuous electroplating apparatus, but as described above, the present invention can also be used for specifying a flaw-causing roll in a rolling apparatus or the like. Of course.

[0021]

As described above, according to the flaw-causing roll detection method of the present invention, in order to specify the causal roll by setting the specific section corresponding to each roll on the steel sheet, the defective quality section As a result, it is possible to shorten the section of the steel plate that has to be discarded, and to quickly and surely identify the cause roll.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a detection mechanism of a causal roll that causes a flaw.

FIG. 2 is an explanatory diagram showing a method of forming a specific section.

FIG. 3 is an explanatory diagram showing another method of forming a specific section.

[Explanation of symbols]

 1 Continuous electroplating device (pressurized section) 3 Defect confirmation device 5 DDC (direct digital controller) 7 Line controller Ri conductor roll (roll) S Steel plate Xi specific section

Claims (1)

[Claims] 1. When a plurality of rolls are continuously arranged and pressure is applied by passing these steel plates, when a flaw is generated in the steel plate, a pair of rolls is provided in one section of the steel plate. A specific section corresponding to one and having at least the same length as the circumference of the roll is formed, and when these specific sections of the steel plate pass through the corresponding rolls, respectively, the roll is opened to apply pressure. A method for detecting a defect-causing roll, which is characterized in that a specific section in which a defect has not occurred is detected and a roll corresponding to this specific section is specified as a defect-causing roll.