JP4323736B2 - LP steel plate sampling position determination method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for determining a sampling position of LP steel plates (steel plates having different thicknesses in the longitudinal direction) having dimensions specified by order from a material to be rolled.
[0002]
[Prior art]
Since LP steel sheets can be manufactured in advance to have a cross-sectional dimension corresponding to the load distribution in the longitudinal direction, they are extremely rational when used for general structural members, and are extremely effective in reducing material weight and saving materials. is there. This LP steel sheet has a flat plate shape as in the case of a steel sheet having a constant thickness in the longitudinal direction (hereinafter referred to as a flat plate), and the sampling position from the material to be rolled is not determined, and the thickness in the longitudinal direction must be considered. Don't be.
As a method for collecting an LP steel plate (order LP steel plate) having a dimension designated by this order from a material to be rolled, there has been a proposal in, for example, Japanese Patent Laid-Open No. 7-185604. In this method, the sheet thickness profile in the longitudinal direction of the material to be rolled is measured with a thickness meter, and the position where the measured value matches the maximum thickness and the minimum thickness of the custom LP steel sheet is determined as the sampling position.
[0003]
[Problems to be solved by the invention]
However, in the above method, the sampling position of the custom LP steel plate is determined only by the nominal thickness (product thickness) of the two custom LP steel plates of the maximum thickness and the minimum thickness. It is difficult to roll the part, and the thickness deviation at the taper part becomes large, and the tolerance of the nominal thickness of the custom LP steel sheet at the taper part (the plate thickness difference allowed for the product thickness) is likely to be off. In some cases, the yield was lowered, and when the tolerance was outside the upper limit tolerance, the grinder or the like had to be maintained so as to be within the tolerance. Further, in this method, the sampling position cannot be determined for the LP steel plate composed of a combination of one or more flat plate portions and tapered portions.
An object of the present invention is to obtain the LP steel sheet closest to the nominal thickness of the custom LP steel sheet by accurately determining the sampling position of the custom LP steel sheet from the material to be rolled.
[0004]
The present invention has been made in order to solve the above-mentioned problems, and the means 1 has a sampling margin for the ordered LP steel sheet from the rolled material from the product collection effective range length of the rolled material and the length of the ordered LP steel sheet. Determine the range, divide the sampling margin range, obtain the evaluation value from the plate thickness measurement value and the nominal thickness at a plurality of measurement points within the product sampling effective range starting from the division point, and the evaluation value is the smallest An LP steel plate sampling position determination method characterized in that a division point is a front position for order LP steel plate sampling .
In the means 2, the dividing point with the smallest evaluation value is a position where the difference between the nominal thickness of the ordered LP steel plate and the measured thickness is squared for each dividing point, and the sum of them is the smallest. It is the sampling position determination method of the LP steel sheet described in Means 1.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The present invention sequentially moves the sampling position of the custom LP steel sheet in the longitudinal direction of the material to be rolled within the product collection range of the material to be rolled. A position where the difference in the nominal thickness in the longitudinal direction is the smallest is obtained, and this position is determined as the sampling position of the custom LP steel sheet to obtain the LP steel sheet closest to the nominal thickness of the custom LP steel sheet.
[0006]
Hereinafter, specific embodiments thereof will be described with reference to FIGS.
The planar shape of the material 1 to be rolled is measured by a flat shape meter or the like, and the crop portion CF of the front F and the crop portion CT of the tail T of the material 1 are detected. The length L of the product collection effective range M of the material to be rolled 1 excluding the both cropped portions CF and CT is obtained. A difference ΔL between the length L of the product collection effective range M and the length Lp of the order LP steel plate 2 is obtained, and this difference ΔL is obtained from the product collection effective range M of the material 1 to be rolled. Front range).
[0007]
This will be described in detail with reference to FIG. The front position A of the product collection effective range M of the material 1 to be rolled A when the order LP steel plate 2 is positioned closest to the front F side with respect to the product collection effective range M of the material 1 to be rolled A Product of the product rolling effective range M of the removed rolled material 1 is determined, and the product of the rolled material 1 when the custom LP steel plate 2 is positioned closest to the tail T side of the product sampling effective range M is determined. Tail position of sampling effective range M (rolled material that becomes tip of custom LP steel plate 2 when rear end of product sampling effective range M of rolled material 1 is positioned as rear end of custom LP steel plate 2 1 position) B is determined, and the length between AB is defined as a front range ΔL.
[0008]
Further, as shown in FIG. 2, the thicknesses ta0 to tal at a plurality of positions in the longitudinal direction of the product collection effective range M excluding the front CF of the material 1 and the crop portions CF and CT of the tail T are measured. The front range of the rolled material 1 is divided into m (FIG. 3).
Next, the tip position of the order LP steel plate 2 is matched with the 0th position of this division point (the front position A of the product collection effective range M of the material 1 to be rolled). Then, in the total length of the custom LP steel plate 2, the measurement plate thickness ta0 to tan within the range is compared with the nominal thickness tp0 to tpn of the custom LP steel plate 2 at each point, and a difference of 2 at each measurement position is calculated. The power values are obtained and summed up to obtain the evaluation value V. That is, when the number of the thickness measurement points in the longitudinal direction of the material to be rolled is n in the total length of the custom LP steel plate, the thickness of the custom LP steel plate at the j-th (0 ≦ j ≦ n) measurement point is tp (j ), Where the measured thickness of the rolled material at that position is ta (j), the evaluation value V = Σ (tp (j) −ta (j)) ² . However, if there is at least one point where the measured plate thickness tp (j) of the material 1 to be rolled <the plate thickness ta (j) of the custom LP steel plate 2, the evaluation value is not calculated and the sampling position is not assumed. .
[0009]
This is sequentially performed until the 1st to m-th division positions (position B of the material 1 to be rolled at the tip of the custom LP steel plate 2) in the front range ΔL of the material 1 to be rolled.
Then, the position where the evaluation value becomes the smallest value (any one of the 0th to mth positions) is determined as the front position of the order LP steel plate from which the order LP steel plate 2 is collected.
The evaluation value is such that the smaller the size of the nominal thickness of the order LP steel plate, the smaller the value, and the calculation method is to divide the order LP steel plate 2 into a plurality of parts in the longitudinal direction and order LP at each division point. The square of the difference between the nominal thickness of the steel sheet and the measured thickness at that position is calculated and summed. Actually, the thickness measurement result is not always equal to the actual thickness due to disturbance due to accuracy error, noise, etc., and therefore, the thickness measurement result is set to be more strict than the upper and lower limit tolerances.
[0010]
Details of the evaluation method will be described with reference to FIGS. In the case of FIG. 5, there is a point (point C) in which the thickness of the material 1 to be rolled exceeds the tolerance upper limit tu of the nominal thickness of the custom LP steel plate 2, and in the case of FIG. 7, the thickness of the material 1 to be rolled However, since there is a point (point D) that falls below the tolerance lower limit tl of the nominal thickness of the custom LP steel plate 2, in these cases, the evaluation value is not calculated and the boarding position is not obtained. In addition, when the thickness of the material 1 to be rolled falls within the tolerance of the custom LP steel plate as shown in FIG. Decide where to collect the products to be ordered. By the above method, a product is collected such that the thickness of the material 1 to be rolled falls within the tolerance of the custom LP steel plate, and the difference between the thickness of the material 1 to be rolled and the nominal thickness of the custom LP steel plate is minimized. Is possible.
[0011]
【The invention's effect】
As described above, according to the present invention, it is possible to collect the LP steel sheet as a product at a position where the thickness of the material 1 to be rolled is closest to the thickness of the custom LP steel sheet, and therefore reject the product. The rate is greatly reduced and the yield is improved, and the maintenance work by the grinder and the like is greatly reduced, and the production cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view showing a relationship between a custom LP steel plate and a material to be rolled.
FIG. 2 is a side view showing a plate thickness in a longitudinal direction of a material to be rolled.
FIG. 3 is a plan view showing a division state of a front range.
FIG. 4 is a side view showing the thickness of the custom LP steel plate in the longitudinal direction.
FIG. 5 is a side view showing the relationship between the thickness tolerance of a custom LP steel plate and the thickness of a rolled material.
FIG. 6 is a side view showing the relationship between the thickness tolerance of a custom LP steel plate and the thickness of a material to be rolled.
FIG. 7 is a side view showing the relationship between the thickness tolerance of the custom LP steel plate and the thickness of the material to be rolled.
[Explanation of symbols]
1 Rolled material 2 Order LP steel plate M Product collection effective range F Front CF Front crop part T Tail CT Tail crop part ΔL Sampling margin range (front range)
tu Tolerance upper limit tl Tolerance lower limit

Claims (2)

Determine the sampling margin range of the ordered LP steel sheet from the rolled material from the length of the product sampling effective range of the rolled material and the length of the ordered LP steel sheet, divide the sampling margin range, and collect the product starting from the division point An LP steel plate sampling position characterized in that an evaluation value is obtained from a plate thickness measurement value and a nominal thickness at a plurality of measurement points within an effective range, and a division point having the smallest evaluation value is set as a front position for order LP steel plate sampling. Decision method. The dividing point with the smallest evaluation value is a position where the difference between the nominal thickness of the ordered LP steel sheet and the measured thickness is squared for each dividing point, and the sum of them is the smallest position. sampling method of locating LP steel sheet according to claim 1.

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