JPH04224017A - Method for detecting roll making cause of flaw - Google Patents

Abstract

PURPOSE:To quickly and surely specify a roll which makes a cause for generating a flaw when the flaw is generated on the surface of a pressed steel plate in an electroplating system and a rolling mill, etc., having pressurizing blocks by plural rolls. CONSTITUTION:Plural specified blocks Xi which, correspond in pairs to each roll Ri in one block of a steel plate S and plural specified blocks Xi having lengths equal to the peripheries of these rolls Ri are formed, each roll Ri is controlled so that it does not exert pressurizing force in the respective corresponding specified block Xi, in this way a specified block Xi in which the flaw has not occurred is detected, thereby the rolls Ri corresponding to these specified blocks Xi are specified as the cause rolls.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] When a flaw occurs on the surface of a steel plate in a pressurizing section of the steel plate in an electroplating device, a rolling device, etc., the present invention quickly and reliably removes the roll that caused the flaw. Regarding how to identify.

0002

BACKGROUND OF THE INVENTION Conventional methods for detecting flaws on the surface of a steel sheet caused by rolls in a pressurized section by rolls include, for example, the method disclosed in Japanese Patent Application Laid-open No. 80321/1983 (first conventional method). This method detects the occurrence of flaws caused by the rolls by paying attention to the periodicity of the flaws formed by the rolls.

[0003] Furthermore, as a conventional method for identifying the roll that caused this flaw, for example, Japanese Patent Laid-Open No. 52-9
Method disclosed in Publication No. 3385 (referred to as second conventional example)
This method similarly focuses on the periodicity of flaws, and identifies the roll causing the flaw from the interval between flaws, taking into account the diameter of each roll and the elongation rate due to pressure.

0004

[Problems to be Solved by the Invention] However, the method of the first conventional example described above is a method for simply determining whether or not a flaw formed on the surface of a steel sheet was formed by a roll; When a plurality of rolls are consecutively arranged in a section, it is not possible to specify which roll caused the flaw. In addition, although it is possible to identify the causative roll depending on the method of the second conventional example, since a minute elongation rate is used as a parameter (variable) during calculation, there is a large error, especially when the diameter of each roll is the same. There was a problem in that there was little change in the interval between flaws, making it difficult to identify the causative roll.

Furthermore, in these conventional examples, in order to measure the periodicity of flaws, a rather long section must be wasted as a detection section without being able to identify the roll causing the defect, resulting in a problem of poor yield. also occurs. Therefore, the present invention proposes a method for detecting the roll causing the flaw, which can shorten the period of poor quality and can quickly and reliably identify the roll that caused the flaw. The purpose is to

[0006]

[Means for Solving the Problems] The present invention provides that, when a flaw occurs in a steel plate passing through a pressurizing section, a flaw occurs in one section of the steel plate, and the flaw corresponds one-to-one to each roll in the pressurizing section, and at least one of the rolls is damaged. In addition to forming specific sections having the same length as the circumference, when these specific sections of the steel plate pass through the respective corresponding rolls, the rolls are opened and no pressure is applied, so that no flaws occur. The above problem has been solved by proposing a method for detecting a roll causing a flaw by detecting a specific section and identifying the roll corresponding to this specific section as the roll causing the flaw.

[0007]

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

[0008] Therefore, since no defects occur in the specific section corresponding to the roll that caused the defect, the cause roll is identified by inspecting each specific section and detecting the specific section where no defects occur. . At this time, since it is only necessary to inspect a specific section to detect the roll causing the flaw, the number of sections discarded as poor quality is shorter compared to the method of identifying the roll causing the defect by checking the periodicity of the flaw. Detection work becomes faster and more reliable.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the method of the invention will be described with reference to FIGS. 1 to 3. FIG. 1 is an explanatory diagram of means for identifying a roll causing a flaw. The continuous electroplating apparatus 1 has a plurality of sets of conductor rolls Ri (i=1, 2, 3,
...) are arranged in succession, and the device 1 serves as a pressurizing section and has a structure in which the steel plate S is passed from the left side to the right side in the figure. Moreover, on the exit side of the steel plate S of this device 1,
A confirmation device 3 for the observer W is installed, and a confirmation button 4 is attached to the device 3 to confirm that the flaw has disappeared. Further, a DDC (direct digital control device) 5 is arranged near the continuous electroplating device 1, and this DDC 5 controls the opening and closing of each conductor roll Ri, and also controls the control state in the operator's cab 6. The structure is such that the information is displayed on the line control device 7.

Next, the operation of each device will be explained, focusing on the DDC 5. First, if a flaw occurs during line operation,
The worker V who controls the line instructs, via the control device 7 in the operator's cab 6, to start identifying the roll Rc that caused the flaw in the DDC 5 (FIG. 1, relationship line ■). On the other hand, D
DC5 connects any section of the steel plate S to each conductor roll R.
A plurality of specific sections Xi (i=
1, 2, 3,...). Then, the opening and closing of each conductor roll Ri is controlled so that each conductor roll Ri does not pressurize the corresponding specific section Xi (relation line ■ in the figure).

Here, the length L of the specific section Xi is L=πD+ where D is the diameter of the conductor roll R and α is the adjustment value.
α...(1) is set as follows. That is, each conductor roll Ri makes at least one revolution in each specific section Xi to press its side surface against the steel plate S.

[0012] The supervisor W monitors whether or not the flaw has disappeared at point A on the exit side of the continuous electroplating apparatus 1, and presses the confirmation button 4 when the part where the flaw has disappeared has reached point A. , and inputs that information to the DDC 5 (relation line ■). on the other hand,
In parallel with this work, the DDC5 controls the moving speed of the steel plate S,
The passage status of the steel plate S is constantly tracked from the distance between point A and each conductor roll Ri, and it is detected which specific section Xi passes through point A (relationship line ■
). That is, based on the information on the confirmation button 4 and the information on the passing status of the steel plate S, it is possible to determine in which specific section Xi the flaw has disappeared, and from this, the DDC 5 identifies the cause roll Rc and sends the information to the CRT of the control device 7. (Relation line ■).

Next, the procedure for forming the above-mentioned specific section Xi will be explained based on FIG. 2. For ease of explanation, the continuous electroplating apparatus will be described as having only three conductor rolls R1-R3. First, at point A,
When a flaw is discovered on the steel plate S (FIG. 1 (1)), the DDC 5 immediately opens the first roll R1 (FIG. 1 (2)). As mentioned above, this release is determined by the roll circumference length (πD+
α) and set this part as the first specific section X1 (
Same figure (3)). Next, when the end of this first specific section X1 reaches the second roll R2, the DDC5 moves the second roll R2.
2 is opened ((4) in the same figure), and a second specific section X2 of the roll circumference length is similarly formed ((5) in the same figure).

On the other hand, when the tip of the specified section X1 approaches point A, the supervisor W starts checking for the presence of flaws ((6) in the figure). Then, when the steel plate S advances and the end of the second specific section X2 reaches the third roll R3, the DDC 5 similarly releases the third roll R2 ((4) in the figure),
A third specific section X3 of the roll circumference length is formed (see FIG.
7), (8)). In addition, the flaw checking work that was carried out in parallel with the setting of these specific sections
This is repeated until the point is passed ((9) in the same figure). In addition, the defective area L is from the first roll R1 to point A when the flaw is discovered (Fig. 2 (1)), and the sum of this distance L and the continuous area used for detection (3(πD+α)) is This is a discarded section that cannot be used as a product.

[0015] Here, each roll R1 to R3 is a specific section X.
1 to X3 respectively, and each roll R as described above.
i presses the steel plate S avoiding each corresponding specific section Xi. That is, the first specific section X1 includes the second roll R2, the third roll
Due to roll R3, the second specific section X2 is the first roll R1
, the third specific section X3 is pressed by the first roll R1 and the second roll R2. Therefore, if a specific section Xi where the flaw has disappeared is detected, the roll Ri corresponding to this specific section Xi is the causative roll Rc (for example, if the flaw has disappeared in the second specific section X2, the second roll R2 is (the cause role Rc), it is possible to easily identify the cause role Rc. Furthermore, at this time,
The DDC 5 constantly tracks the steel plate S and knows 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 released ((2) in the same figure). Then, when the steel plate S moves by πD+α, the first roll R1 is closed to form a first specific section X1 here. At the same time, the third roll R3 is released ((3) in the same figure), and a third specific section X3 is formed ((4) in the same figure). Furthermore, when the steel plate S progresses and the specific section X1 reaches point A, detection of flaws is started, and when the end of the first specific section (5)), and a second specific section X2 is formed here ((6) in the same figure). Thereafter, flaws in the first and second specific sections X1 and X2 are sequentially detected, and the series of operations is completed ((7) in the figure).

[0017] In this forming method, since the third specific section X3 is formed within the above-mentioned defective section L, the discarded section having no commercial value can be made shorter. That is,
Depending on the formation method shown in FIG. 2, the discard section may be L+3(
πD+α), but 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
can automatically identify the role Rc that caused the flaw by simply checking that the flaw has disappeared, without paying attention to which specific section Xi is currently passing through point A. In particular, in this embodiment, since a plurality of rolls Ri are not opened at the same time, the plating conditions are not disturbed.
The high quality of the steel plate S can be maintained. In addition, in a rolling apparatus or the like that does not have such constraints, 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.

Furthermore, when this embodiment was used on an actual line, the distance for discarding the steel plates S required to identify the roll responsible was only about 100 m, whereas each roll R
In the conventional method of opening i one set at a time and checking the results, the length was about 3000 m, and it was found that the method of this example has a great effect in increasing production efficiency. Although this embodiment relies on the human eye to detect flaws, a flaw detection device equipped with an image processing device may be installed instead.

Furthermore, although this embodiment is an example in which the present invention is applied to a continuous electroplating apparatus, as mentioned above, the present invention can also be used to identify rolls that cause defects in rolling machines, etc. Of course.

[0021]

[Effects of the Invention] As explained above, depending on the method of detecting rolls causing defects of the present invention, specific sections are set on the steel plate in one-to-one correspondence with each roll, and in order to identify the roll causing defects, It is possible to shorten the section of steel plate that must be discarded, and to quickly and reliably identify the roll causing the problem.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a mechanism for detecting a 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 equipment (pressure section) 3
Defect disappearance confirmation device 5 DDC (Direct Digital Control Device)
7 Line control device Ri Conductor roll (roll) S
Steel plate Xi specific section

Claims (1)

[Claims] Claim 1: When a flaw occurs in a steel plate in a pressurizing section where a plurality of rolls are consecutively arranged and the steel plate is passed through and pressurized, a pair of rollers is placed on each of the rolls in one section of the steel plate. forming specific sections that correspond to one another and having at least the same length as the circumference of the roll, and when these specific sections of the steel plate pass through the respective corresponding rolls, the rolls are opened and pressurized. A method for detecting a roll causing a flaw, the method comprising: detecting a specific section in which no defects occurred, and identifying the roll corresponding to this specific section as the roll causing the flaw.