JP3258499B2 - Board camber straightening method - 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 correcting a plate camber such as a thick steel plate.

[0002]

2. Description of the Related Art In general, the following method is used for camber correction of a board. (B) Three-point repetitive bending method As shown in FIG.
The two pressing devices 13 and 14 are disposed on the concave side of the camber, and one pressing device 15 is disposed on the convex side of the camber so that the plates are successively transported in the longitudinal direction sandwiched by 12. I do. That is, the rolling load P determined by the plate thickness t, the plate width W, the Young's modulus E of the material, and the yield stress σ is set, and two relatively close points on the concave side of the camber are supported while the plate 10 is sequentially conveyed, and the center thereof is supported. The three-point bending to reduce one point on the convex side of the camber is repeated many times in the longitudinal direction of the plate, and after that, the camber amount is measured, and the entire length of the plate is repeatedly corrected until the measured value falls within the set allowable value. . (B) A straightening method using a flanged leveler.

[0003] As shown in a side view in Fig. 8A and a plan view in Fig. 8B, a method in which the flanges 22 are alternately mounted, and the straightening is performed by the flange of the leveler roller 21 to which the thrust bearing 23 is mounted. , Is used when the plate 10 is a narrow material.

[0004]

The conventional three-point repetitive bending method has the following problems. (1) Local camber correction can be performed, but camber of the full length of the board cannot be corrected at one time. Therefore, work efficiency is poor. (2) With the three-point bending, a uniform bending moment distribution optimal for straightening cannot be obtained. In addition, it may cause breakage of the plate. (3) Since it is necessary to repeatedly perform the correction many times, it takes a long time to correct one plate. (4) The rolling load is often determined by the experience of the operator, but the setting error of the rolling load P has a great influence on the corrected plate shape.

[0005] In addition, the bending straightening method using the above-mentioned flanged leveler has the following problems. (1) The bending accuracy is poor and cannot be corrected with high accuracy. (2) For wide members, the deformation does not reach the center of the plate, so that it cannot be corrected.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems. In correcting the plate camber, the upper and lower surfaces of the plate are restrained so that out-of-plane deformation does not occur in the plate. A plate camber correction method characterized in that a bending moment is applied to the plate at both ends of the plate or at one or more places other than both ends and both ends of the plate to correct the camber over the entire length of the plate.

[0007]

[Action] the curvature of the correction before the plate and 1 / ρ _0, the curvature of the plate after the correction of the target and the ₁ / ρ 1. According to the present invention, a bending moment that causes a change in curvature of the difference (1 / ρ ₁ −1 / ρ ₀ ) is applied to both ends of the plate, and a uniform bending moment is applied to the entire length of the plate to thereby reduce the total length of the plate. The camber can be corrected. In addition, during camber correction, the plate is pressed from the upper and lower surfaces of the plate so that out-of-plane deformation does not occur.

FIGS. 3 and 4 show a method for straightening a plate camber according to the present invention.
It will be explained by. (A) The difference (1 / ρ ₁ −1 / ρ ₀ ) between the curvature 1 / ρ ₀ of the plate before correction and the target curvature 1 / ρ ₁ of the plate after correction is determined. _{(B) (1 / ρ 1} -1 / ρ 0) plastically bending the bending moment M that causes the _{(1 / ρ 1 -1 / ρ} 0), Itacho L, thickness t, the plate width W, Then, the bending moment M is applied to both ends of the plate, the bending moment M is applied to the entire length of the plate, and then removed.

If (1 / ρ ₁ −1 / ρ ₀ ) is not constant in the longitudinal direction of the plate, as shown in FIG. By applying a bending moment at one or more locations, (1 / ρ ₁ −1 / ρ
_A bending moment close to the plastic bending moment of ₀ ) can be generated over the entire length of the plate.

By the straightening method according to the above steps (a) and (b), it is possible to obtain a sheet having a target sheet curvature of 1 / ρ ₁ after the correction. In the present invention, since a bending moment is applied to both ends of the plate, a large tensile or compressive stress is generated at the edge portion of the plate, and the plate may be out-of-plane deformed particularly on the compression side, causing out-of-plane bending or bending. There is.
Therefore, it is necessary to provide an out-of-plane deformation pressing device which abuts against the upper and lower surfaces of the plate to prevent the plate from being deformed. Since such a device needs to be arranged according to the length of the plate, in the vicinity of the longitudinal end of the plate, using a device with a short dimension in the plate length direction for longitudinal adjustment,
Use selectively.

[0011]

FIG. 1 is a plan view showing an apparatus according to an embodiment of the present invention.
FIG. 2 is an elevational view of a portion thereof. The plate 10 for correcting the camber is transported by the pinch roller 2. The plate 10 is clamped by bending moment load devices 3a, 3b; 3c, 3d. The bending moment load devices 3c, 3d can be moved in the plate longitudinal direction by a positioning device 4 according to the length of the plate.

Bending moment load devices 3a, 3b; 3
In c and 3d, a clamping device for firmly clamping the plate from above and below is provided, and an arm is attached to the device, and a device for rotating the arm in a direction for applying a bending moment in the correction direction to the plate is provided. The out-of-plane deformation pressing device 5 is configured to press the plate from above and below so that the plate does not undergo out-of-plane deformation. FIG.
A value obtained by removing (1 / ρ ₁ −1 / ρ ₀ ) by the elastic limit curvature, that is, a value of (1 / ρ ₁ −1 / ρ ₀ ) / (1 / ρ _y ) and (1 / ρ ₁ −1) / [rho ₀ bending moment M causes a plastic bending) shows the relationship between the value of a value obtained by dividing i.e. M / M _y in elastic limit bending moment. Here, 1 / ρ _y: elastic limit of curvature = 2σ _y / EW σ _y: yield stress of the plate material E: Young's modulus of the plate W: strip width M: Plastic Bending of _{(1 / ρ 1 -1 / ρ} 0) causing bending moment M _y: elastic limit bending moment ^{_{= 1 / 6σ y W 2 t}} t: a plate width.

According to FIG. 5, the plate length L = 10 m, the curvature before correction 1 / ρ ₀ = 8 × 10 ⁻⁵ mm ⁻¹ (the camber before correction C ₀ = 1)
0 mm), W = 480 mm, t = 8 mm, σ _y = 40 k
gf / mm ² , E = 21000 kgf / mm ²
Assuming that the curvature after the correction is 1 / ρ ₁ = 0 and the bending moment M is applied to both ends to perform the correction, the curvature after the correction 1 / ρ ₁ = ± 8 × 10 ⁻⁶ mm ⁻¹ (after the correction) (Camber C ₁ = ± 1 mm).

In the prior art, in one correction, the camber amount after correction C ₁ = ± 10 mm from the initial camber amount C ₀ = ± 10 mm.
It could only be about 5 mm and had to be repeatedly corrected. In the embodiment, however, the camber amount after correction C
₁ could be within ± 1 mm. In the above embodiment, the case where one bending moment load device is movable according to the plate length has been described.However, both bending moment load devices may be movable, and a plurality of devices of the same type may be installed. Alternatively, an apparatus may be used in which an apparatus is selected and used according to the plate length.

[0015]

The present invention relates to the correction of board camber,
After pressing the plate from the top and bottom surfaces so that out-of-plane deformation does not occur on the plate, apply a bending moment to the plate at one or more places other than both ends of the plate or even both ends,
It can be corrected over the entire length of the board. In addition, since the deformation occurs over the entire length, there is also an effect that a local decrease in the strength of the plate can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is an elevation view showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing the operation of the present invention.

FIG. 4 is an explanatory diagram showing the operation of the present invention.

FIG. 5 is a graph showing a bending moment M applied for correcting a plate camber.

FIG. 6 is an explanatory diagram showing an embodiment of the present invention.

FIG. 7 is an explanatory view of a related art.

FIG. 8 is an explanatory view of a related art.

[Explanation of symbols]

 2 Pinch Rollers 3a, 3b, 3c, 3d Bending Moment Load Device 4 Positioning Device 5 Out-of-Plane Deformation Pressing Device 10 Plate 11, 12 Pinch Roller 13, 14, 15 Push-Down Device 21 Leveler Roller 22 Flange

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-60352 (JP, A) JP-A-7-60353 (JP, A) JP-A-3-297516 (JP, A) JP-A 8- 90070 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B21D 1/06

Claims (1)

(57) [Claims] In correcting a plate camber, the upper and lower surfaces of a plate are restrained so that out-of-plane deformation does not occur in the plate, and bending moment is applied to the plate at both ends of the plate or at one or more places other than both ends and both ends of the plate. In addition, a flat camber correction method characterized by correcting the camber of the entire length of the board at one time.