阅读说明：本技术 一种金属厚板压平工艺模型 (Metal thick plate flattening process model ) 是由 桂海莲 邢彤 王荣军 王亚东 楚志兵 李玉贵 于 2019-09-19 设计创作，主要内容包括：本发明公开了一种金属厚板压平工艺模型,通过扫描压平件的形貌得到压平件的板形曲线方程,从而得到压平机垫块距离以及压平件的原始挠度,结合得到的压平量的计算公式,即可确定压头位置以及压下量,实现一次矫直合格率95％以上,从而提高工作效率,减少压平工艺对人工的依赖,减少操作人员的劳动强度,实现自动化。(The invention discloses a metal thick plate flattening process model, which obtains a plate shape curve equation of a flattening piece by scanning the shape of the flattening piece so as to obtain the distance of a cushion block of a flattening machine and the original deflection of the flattening piece, and can determine the position of a pressure head and the pressing amount by combining the obtained flattening amount calculation formula so as to realize the primary straightening qualification rate of more than 95 percent, thereby improving the working efficiency, reducing the dependence of the flattening process on the manual work, reducing the labor intensity of operators and realizing the automation.)

1. A metal thick plate flattening process model is characterized by comprising the following steps:

s1: equation of the plate shape curve of the flattening

Carrying out appearance scanning on the thick plate flattening piece, analyzing the original deflection of the flattening piece and the wave height central position of the flattening piece by utilizing scanning information, and obtaining a plate shape curve equation of the flattening piece according to the scanning information of the flattening piece:

δ₀-the original deflection of the flattening element,

l is the distance between cushion blocks of the flatting machine and is determined by a plate-shaped curve obtained by scanning;

obtaining the distance of a cushion block of a flattening machine and the original deflection of the flattening piece according to a plate-shaped curve equation of the flattening piece;

s2: calculation formula of rolling reduction

In the traditional straightening theory, when elastic deformation is achieved and elastic deflection is equal to reverse bending deflection, the plate is considered to be straightened and flat, namely

δ_f＝δ_w(2)

δ_f-the degree of resilience deflection,

δ_w-reverse bending deflection;

defining the original curvature ratio: c₀＝A_o/A_tThe reverse bend ratio: c_w＝A_w/A_t，

A_o-the original curvature of the flattened piece,

A_wthe reverse bend ratio after being subjected to the pressure,

A_t-the elastic limit curvature of the material itself;

wherein the proof curvature is:

σ_tthe limit of elasticity of the material, however,

e-modulus of elasticity of the material,

h-thickness of material;

according to the stress-strain relationship of the thick plate during bending, assuming that the thick plate material is an ideal material, since the thick plate is approximately considered as a rectangular section during flattening, the external force distance to which the thick plate is subjected during bending is as follows:

b-the width of the material,

H_t-the elastically strained thickness of the material;

defining a bending moment ratio:

M_t-the elastic limit bending moment of the material;

achieve the successful flattening by

C_w ³+(2C₀-1.5)C_w ²+(C₀ ²-3C₀)C_w-1.5C₀ ²+0.5＝0 (6)

from equation (6), C can be obtained_wTherefore, the theoretical reduction:

δ₁＝δ₀+δ_w＝δ₀+C_wδ_t(7)

δ_t-the elastic limit deflection of the material;

therefore, the actual rolling reduction of the flatting machine is as follows:

δ₂＝αδ₁(8)

alpha is the actual weighting coefficient of the rolling reduction of the flattening machine;

comparing a plurality of groups of flattening amount values calculated by the formulas (1) to (8) with a set of actual flattening amount values to obtain a calculation formula of the pressing amount of any different original deflection, the yield strength of the material and the plate thickness under the same fulcrum:

σ_Sthe yield strength of the flattened piece,

h is the thickness of the plate of the flattening piece,

δ₀-the original deflection of the flattening element,

α₁、α₂-a calculated factor in the reduction;

s3: calculation of the reduction

Determination of alpha in equation (9) by the actual applanation value₁、α₂And calculating the random different original deflection, the yield strength of the material and the reduction of the plate thickness under the same pivot point according to the formula (9).

Technical Field

The invention belongs to the technical field of pressure straightening, and particularly relates to a metal thick plate flattening process model.

Background

When the plate shape defect occurs in the production process of the medium plate, the medium plate needs to be finished by means of straightening equipment. When the thickness of the plate is more than 40mm, a roller straightening machine cannot be used for straightening, so that a flattening machine is selected for quick and accurate straightening. However, the existing flattening process has no reasonable model, is basically determined by the experience of operators, has great uncertainty on the bending position and the pressing amount of a pressing head, has no reasonable flattening procedure, needs to repeatedly bend for inexperienced operators for many times, and seriously restricts the working efficiency.

Disclosure of Invention

In view of this, the invention aims to provide a metal thick plate flattening process model, which can effectively improve the accuracy of the pressing amount of a flattening machine, ensure the flattening precision and the quality of a thick plate, and improve the working efficiency.

In order to achieve the purpose of the invention, the technical scheme is as follows:

a metal thick plate flattening process model comprises the following steps:

s1: equation of the plate shape curve of the flattening

Carrying out appearance scanning on the thick plate flattening piece, analyzing the original deflection of the flattening piece and the wave height central position of the flattening piece by utilizing scanning information, and obtaining a plate shape curve equation of the flattening piece according to the scanning information of the flattening piece:

δ₀-the original deflection of the flattening element,

l is the distance between cushion blocks of the flatting machine and is determined by a plate-shaped curve obtained by scanning;

obtaining the distance of a cushion block of a flattening machine and the original deflection of the flattening piece according to a plate-shaped curve equation of the flattening piece;

s2: calculation formula of rolling reduction

In the traditional straightening theory, when elastic deformation is achieved and elastic deflection is equal to reverse bending deflection, the plate is considered to be straightened and flat, namely

δ_f＝δ_w(2)

δ_f-the degree of resilience deflection,

δ_w-reverse bending deflection;

defining the original curvature ratio: c₀＝A_o/A_tThe reverse bend ratio: c_w＝A_w/A_t，

A_o-the original curvature of the flattened piece,

A_wthe reverse bend ratio after being subjected to the pressure,

A_t-the elastic limit curvature of the material itself;

wherein the proof curvature is:

σ_tthe limit of elasticity of the material, however,

e-modulus of elasticity of the material,

h-thickness of material;

according to the stress-strain relationship of the thick plate during bending, assuming that the thick plate material is an ideal material, since the thick plate is approximately considered as a rectangular section during flattening, the external force distance to which the thick plate is subjected during bending is as follows:

b-the width of the material,

H_t-the elastically strained thickness of the material;

defining a bending moment ratio:

M_t-the elastic limit bending moment of the material;

achieve the successful flattening by

So equation (5) is converted to:

C_w ³+(2C₀-1.5)C_w ²+(C₀ ²-3C₀)C_w-1.5C₀ ²+0.5＝0 (6)

from equation (6), C can be obtained_wTherefore, the theoretical reduction:

δ₁＝δ₀+δ_w＝δ₀+C_wδ_t(7)

δ_t-the elastic limit deflection of the material;

therefore, the actual rolling reduction of the flatting machine is as follows:

δ₂＝αδ₁(8)

alpha is the actual weighting coefficient of the rolling reduction of the flattening machine;

comparing a plurality of groups of flattening amount values calculated by the formulas (1) to (8) with a set of actual flattening amount values to obtain a calculation formula of the pressing amount of any different original deflection, the yield strength of the material and the plate thickness under the same fulcrum:

σ_Sthe yield strength of the flattened piece,

h is the thickness of the plate of the flattening piece,

δ₀-the original deflection of the flattening element,

α₁、α₂-a calculated factor in the reduction;

s3: calculation of the reduction

Determination of alpha in equation (9) by the actual applanation value₁、α₂And calculating the random different original deflection, the yield strength of the material and the reduction of the plate thickness under the same pivot point according to the formula (9).

The invention has the beneficial effects that: the shape curve equation of the flattening piece is obtained by scanning the shape of the flattening piece, so that the cushion block distance of the flattening machine and the original deflection of the flattening piece are obtained, the position of a pressure head and the pressing amount can be determined by combining the obtained flattening amount calculation formula, the one-time straightening qualification rate is over 95 percent, the working efficiency is improved, the dependence of the flattening process on manpower is reduced, the labor intensity of operators is reduced, and automation is realized.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a view of a flatting machine model;

FIG. 2 is a diagram showing the residual deflection in the width direction after flattening a thick plate having an original deflection of 30 mm.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.