JP3271469B2 - Curve straightening load calculation 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 three-point bending or uniaxial tensioning of a plastically deformable member, for example, a method for straightening a long member such as an elevator guide rail.

[0002]

2. Description of the Related Art The prior art relating to a method of performing a correction while estimating the processing characteristics of a material to be corrected includes the following.

First, a method of measuring the load and the amount of deformation at the time of unloading of one of the lots, storing a relational expression between them as a linear expression, and using the relational expression for correcting another work of the lot. For example, there is JP-A-2-192820. However, the material to be corrected has variations in residual stress and wall thickness due to processing history and the like for each individual and for each position, and the relational expression between the load and the amount of deformation of the material to be corrected cannot be represented by one type. , This point is not taken into account.

Further, as a method of unloading the material to be corrected which is to be currently corrected at a stage where the amount of plastic deformation does not reach the target amount of plastic deformation, and calculating a ratio between a change in load and a change in deformation during unloading,
For example, Japanese Patent Application Laid-Open Nos. 54-135659 and 6-2
No. 77760 is known. In these conventional techniques, since the correction is performed based on the processing characteristics of the current correction position of the current correction target actually measured, in principle, the processing characteristics vary for each material to be corrected and for each position, and the work hardening and the Bauschinger effect. It is possible to perform high-precision correction in one trial without being affected by the above. However, these prior arts are based on the premise that the relationship between the load change and the deformation change at the time of unloading does not change even if pressure is repeatedly applied. However, in actuality, when unloading is performed from different loads, the ratio between the load change and the deformation change at the time when the unloading is completely completed is different. The reason is that the relationship between the load change and the deformation change at the time of unloading is not a linear relationship but a non-linear relationship.
Therefore, high-precision straightening cannot be performed by the conventional technology.

For this reason, the following method has been proposed as a method of performing correction while correcting a calculation formula for determining a pressing load or a deformation amount required for correction and converging within an allowable error with a small number of trials. I have.

First, when a correction result using a predetermined value is excessive or insufficient with respect to a target plastic deformation amount, a ratio between a load change amount and a deformation amount change during unloading at the time of the previous correction is calculated. As a method to be used, there is, for example, JP-A-55-117520. However, even if this conventional technology is used, since only the ratio of the load change and the deformation change when the pressure is applied to one load and then unloaded is used, the correction result is acceptable even if the correction is performed multiple times. There is a problem that it does not easily converge within the error.

Therefore, a relational expression between the total amount of deformation given at the time of straightening and the amount of plastic deformation caused by the straightening is determined by curve regression, and the amount of deformation to be given to the material to be corrected is calculated from the relational expression to perform the correction. As a method for coping with variations or changes in the processing characteristics by recalculating the relational expression using the result when the shortage occurs, for example, Japanese Patent Application Laid-Open No. 63-19 / 1988
No. 9026 was proposed. FIG. 7 shows an explanatory diagram of this prior art. In this prior art, first, a small plastic deformation is applied to a material to be corrected, and a total deformation amount at the start of the plastic deformation, that is, an intercept of a total deformation amount axis in a coordinate system of the total deformation amount and the plastic deformation amount is obtained. Next, a quadratic regression curve of the total deformation amount and the plastic deformation amount at the time of correction is calculated using the intercept and the data of the total deformation amount and the plastic deformation amount when a minute plastic deformation is given. Then, using the regression curve, the total amount of deformation to be applied to obtain the target amount of plastic deformation is calculated. Further, when the correction result is insufficient for the target amount of plastic deformation, the result is added as data and the regression curve is obtained again. If the correction result is excessive with respect to the target amount of plastic deformation, the process returns to the initial intercept calculation. As described above, in the conventional technology, it is possible to cope with the variation in the processing characteristics of each material to be corrected, to cope with work hardening by using a quadratic regression curve, and to cope with the Bauschinger effect by re-determining the regression curve at the time of excessive correction. .

[0008]

However, in the prior art, since the relational expression between the total deformation and the plastic deformation is approximated by a quadratic regression curve, at least three equations are required to determine three unknown parameters of the quadratic function. It is necessary to perform bending twice.

After approximating the relational expression between the total deformation amount and the plastic deformation amount by a quadratic regression curve, the total deformation amount for obtaining the target plastic deformation amount is obtained by extrapolation. In the expression approximated by, the error increases as the deformation amount increases, and the accuracy of calculating the total deformation amount decreases.

Further, when it is necessary to change the pressing direction due to overcorrection, it is necessary to perform bending at least three times in order to obtain the amount of plastic deformation at the start of plastic deformation again.

As described above, the prior art described above has a problem in that it requires four pressurizations at the minimum, and is extremely inefficient.

An object of the present invention is to estimate the variation and change in the processing characteristics at the time of straightening a material to be straightened with as few data as possible, and to obtain an appropriate maximum load under pressure in order to obtain a high-precision plastic deformation amount. Is to seek.

[0013]

In order to achieve the above object, the present invention provides a symbol for identifying an individual material to be corrected, a correction position, a plastic deformation amount required for correction, a maximum pressurizing load during correction, and a plasticity. The amount of deformation is input, the maximum pressurizing load at the time of correction is output, and the maximum pressurizing load at the time of correction, the amount of plastic deformation, a symbol identifying the individual, the correction position, the number of corrections, and the pressing direction are stored. A straightening material bending straightening load calculation method that calculates the relationship between the maximum pressing load and the amount of plastic deformation by calculating the logarithm of each of the maximum pressing force and the amount of plastic deformation when straightening the material to be corrected and obtaining a regression curve. And calculating a target maximum load at the time of correction.

[0014]

[Action] In the deformation of a plastically deformable material, the deformation in the elasto-plastic region is often expressed by the formula

[0015]

(Equation 1)

Can be approximated with sufficient accuracy. Here, σ is a processing force, ε is a displacement amount, and Y, F, and n are real-value constants determined by materials. A special case of the above formula,

[0017]

(Equation 2)

The characteristic represented by is called n-th power curing characteristic.

According to the present invention, the maximum pressurizing load at the time of straightening the material to be straightened is defined as w, and the plastic deformation amount is defined as x.

[0020]

(Equation 3)

The relational expression between the maximum pressurizing load and the amount of plastic deformation is approximated. The n-th power hardening characteristic describes the state during pressurization, and includes elastic deformation and plastic deformation. Strictly speaking, the relationship between the maximum applied load and the amount of plastic deformation cannot be reduced to the n-th power hardening characteristic. Sufficient accuracy can be obtained as an approximation.

According to the present invention, the relational expression between the maximum pressurizing load at the time of correction and the amount of plastic deformation is obtained by approximately using the expression representing the n-th power hardening characteristic. When obtaining the maximum pressurizing load, a high accuracy can be obtained. Further, since the equation representing the n-th power hardening characteristic has only two unknown parameters, if the correction trial is performed twice, it is possible to specify the processing characteristics including the variation between individuals. Further, by storing the relational expression between the maximum applied load and the amount of plastic deformation, high accuracy can be expected in the first and second correction trials. In addition, when it is necessary to change the pressing direction due to overcorrection, the relational expression between the maximum pressing load and the amount of plastic deformation can be obtained using the correction data in the reverse pressing direction. No test bend is required for estimation.

As described above, according to the present invention, the first pressurization already has high correction accuracy, and the target plastic deformation is obtained at a very high ratio by the third pressurization. In addition, even when overcorrection occurs, it is possible to estimate a change in the processing characteristics, and as a result, it is possible to obtain a target amount of plastic deformation by pressurizing about three times on average.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to three-point bending of a long material will be described below with reference to FIG.

FIG. 1 shows the contents of the processing performed by the bending correction load calculation method.

In the correction data input 1, before the correction, the individual number of the long material, the correction position, the pressing direction, and the target plastic deformation amount are input, and after the correction, the maximum pressing load and the plastic deformation amount when the correction is performed. Enter In the correction history storage 2 , the individual number of the long material, the correction position, the pressing direction, and the maximum pressing load and the amount of plastic deformation at the time of performing correction, which are input using the correction data input 1, are numbered in the order of storage. And memorize. The processing characteristic calculation 3 calculates a relational expression between the maximum pressurizing load and the amount of plastic deformation at the time of execution of the correction stored using the correction history storage 2 . The target maximum load calculation 4 includes a target plastic deformation amount and a processing characteristic calculation.
The maximum load required for pressurization is calculated by using the processing characteristics corrected by using No.3 . The target maximum load output 5 outputs a target maximum load calculated using the target maximum load calculation 4 .

An example of the definition of the pressing position and the amount of plastic deformation used in this embodiment will be described in detail with reference to FIG.

It is assumed that the curved shape after pressing P1 on the material to be corrected having the curvature represented by c1 is c2.
The horizontal axis of the coordinate is a straight line connecting both ends of the curve c1 representing the bending of the long material, and the vertical axis is a straight line orthogonal to the coordinate. The projection p1 of the pressing position P1 onto the horizontal axis is defined as pressing position data. Next, a tangent tL to c1 at P1 is taken. Further, the end points bp1 and bp2 on c1 with the length d are taken, a line segment bp1bp2 parallel to tL is taken, and the line segments bp1bp2 and P
Let x1 be the distance to 1. This x1 is called a relative displacement and used for calculating the amount of plastic deformation. Similarly, the processing described above is performed on c2 to obtain x2. At this time, Δ = x2−x
1 is defined as the amount of plastic deformation of the long material.

The definition of the processing characteristics used in this embodiment will be described in detail with reference to FIGS.

FIG. 3 is a graph showing the result of repeatedly applying pressure to one location of one long material in the same direction.
The vertical axis indicates the maximum load at each pressurization. The abscissa indicates a value obtained by summing all the amounts of plastic deformation from the first press after each press. This value is called the accumulated plastic deformation. On the other hand, the amount of plastic deformation caused by only one correction each time is called successive plastic deformation. FIG. 4 is a graph showing the relationship between the maximum load of the data used in FIG. 3 and the logarithm of each cumulative plastic deformation. The logarithm of the data is 2
It is assumed that the following equation is obtained as a result of approximation by a straight line using the multiplication method.

Log w = a log x + b (1) As an approximation method, for example, a perceptron-type neural network may be used instead of the least squares method. This equation (1) is modified as follows.

[0032]

(Equation 4)

Is obtained. Equation 4 represents the processing characteristics of the long material at the time of straightening.

The processing characteristic calculation 3 will be described in detail with reference to FIGS.

FIG. 5 is a diagram showing the relationship between the accumulated plastic deformation in the same direction as the pressing direction and the maximum load in the first pressing when one pressing position of one straightening material is pressed six times. It is.
FIG. 6 shows the cumulative plastic deformation in the direction opposite to the pressing direction and the maximum pressing load in the first pressing with the cumulative plastic deformation before pressing when the pressing direction is changed for the first time set to 0. FIG. FIG. 5 is called a bending-side processing characteristic table.
FIG. 6 is called a bending-back-side processing characteristic table.
Represents correction history data at each pressurization. Is correction history data when pressure is applied in the same direction. Is correction history data when pressure is applied in the reverse direction.
Is correction history data when pressure is again applied in the same direction. When the pressing direction changes for the first time, the processing characteristics change significantly before that time. Pressing under such conditions is called bending back. In this case, the pressing direction returns to the same direction as above, but the processing characteristics do not follow and the processing characteristics are different. Pressurization under such conditions is called bending addition. The amounts of successive plastic deformation in the same direction as the first pressing direction, generated by the first to sixth pressings, are represented by Δ ₁ , Δ ₂ , and Δ, respectively.
_3, Δ _4, Δ _5, and delta _6. The amount of sequential plastic deformation in the opposite direction is represented by a negative value. That is, Δ ₄ and Δ ₅ are negative values. The w _1, respectively the maximum load of each round of _{pressurization, w 2, w 3, w} 4,
Let w ₅ and w ₆ . Also, each time after pressurization, x ₁ first referenced to pressurization the first pressure and the cumulative amount of plastic deformation in the same direction, _{respectively, x 2, x 3, x} 4, x 5, and x _6.
For example, x ₁ = Δ ₁ and x ₂ = Δ ₂ + Δ ₁ . Also,
First referenced to when there is a change in the direction of pressure, referred to as first pressure and cumulative plastic deformation bending back side cumulative plastic deformation of opposite to the direction, each z _1, z _2, z _3, z _4,
z ₅ and z ₆ . For example, _{z 4 = x 4 -x 3 =} Δ 4, z 6 =
x ₆ −x ₃ = Δ ₄ + Δ ₅ + Δ ₆

At the time of the first pressurization, there is no correction history data to be referred to for the current correction position of the current long material. Therefore, using the correction history data obtained when one or more correction positions of one or more long members including the long member are corrected in the same pressing direction, the regression line equation (1) is obtained. n
After the value is calculated, it is transformed into Equation 4 and used as a relational expression between the maximum pressurized load and the amount of plastic deformation.

In the second pressing, when the pressing direction is the same as the first pressing, the correction history data to be referred to for the current correction position of the current long material is only one point. In this case, the same number 4 obtained at the first pressurization is translated in the w-axis direction so as to pass through only one correction history data point. That is, when the first component of the coordinates is the amount of plastic deformation, the second component is the maximum pressing force, and the point is (x ₁ , w ₁ ),

[0038]

(Equation 5)

It is assumed that

In the second pressing, when the pressing direction is opposite to the first pressing, the relational expression between the maximum pressing load and the amount of plastic deformation is obtained in the same manner as in the first pressing.

In the third and subsequent corrections, if all previous corrections have the same pressing direction as this time, the regression line (1) is obtained using all correction history data up to the previous time.
After calculating the formulas and calculating the F and n values, they are transformed into the formula 4 and used as a relational expression between the maximum applied load and the amount of plastic deformation.

In the third and subsequent pressurizations, a description will be given of a case where the pressurization direction has been changed only once before that, that is, a case where bending back has occurred. If the corrections up to the previous time were all in the opposite direction of pressurization, the regression line (1) was calculated using all correction history data up to the previous time, and the F and n values were calculated. And using the constant F ′ obtained by an experiment in advance to the following equation.

[0043]

(Equation 6)

This equation is used as the processing characteristic at the time of bending back. Further, for example, the accumulated plastic deformation amount up to the previous time is defined as x _j, and a constant obtained in advance by experiment is defined as K _F , and F ′ = − K _F x
_jF may be used. Next, if only the previous correction was in the same pressure direction as this time, the regression line (1) was obtained using all the correction history data up to the previous ゝ, and the F and n values were calculated. And is translated in the w-axis direction so as to pass through the previous correction history data point. Also, for example, utilizing the fact that the previous pressurization was the first pressurization after the change in the pressurization direction, virtual correction history data (0, F + F ′) is calculated from F and F ′ calculated next to the previous pressurization. May be set, and Equation 4 may be obtained using this point and the previous correction history data point.
Lastly, if the previous correction was pressurization in the same direction as this time, which was performed two or more times in succession, the regression line (1) was obtained using all the correction history data points in the same direction as this time.
After calculating the n value, it is transformed into the formula 4 and a relational expression between the maximum pressurized load and the amount of plastic deformation is obtained.

In the third and subsequent pressurizations, the case where the pressurization direction has been changed twice or more before that, that is, the case of bending and adding will be described. Note that all pressures after the second change in the pressure direction can be handled as bending additions.

First, when the previous correction was in the same direction as this time, all the correction history data in the same direction as this time are used as long as the correction is continued including the previous time. Of these data, the maximum pressurizing load is added to the data, and Equation 4 is calculated to obtain a relational expression between the maximum pressurizing load and the amount of plastic deformation.

Next, a case where the previous correction is pressurization in the opposite direction to the current correction will be described. The maximum pressurizing load at the time of the previous straightening was w _j , the accumulated plastic deformation amount in the same direction after the previous straightening was x _j , and the last correction history data in the same direction as this time was (x _k , w _k ), the following correction history data (x _j ′, w _j ′) is virtually created using the F and n values used for the previous correction. For distinction, here F is F _j
Write

X _j ′ = x _j , w _j ′ = w _k − (w _j −F) Here, two points (x _k , w _k ), (x _j ′, w _j ′) are translated in parallel. The logarithm of each component of each of the two points (x _k −x _j ′, w _k ) and (0, w _j ′) is obtained, and a regression line is obtained to obtain F, n
Calculate the value. Restore the last translation and finally the following equation:

[0049]

(Equation 7)

Is obtained. This equation is defined as a relational equation between the maximum pressurized load and the amount of plastic deformation.

Finally, it is conceivable that the correction history data is not accumulated at all because the material to be corrected is a new material. In this case, it is necessary to accumulate the correction history data using the first correction position. From the initial value stored in advance, the maximum pressurizing load is increased by a predetermined value stored in advance, and pressure is repeatedly applied from the same direction until two points of plastically deformed correction history data are obtained. However, even in this case, it is possible to converge within an allowable error by performing the bending back and the bending addition depending on the situation, and it is not necessary to use one of the materials to be corrected for the test.

As described above, a method for obtaining the relational expression between the maximum pressurized load and the accumulated plastic deformation in all cases was obtained. When the target amount of plastic deformation is substituted for x in this equation, the maximum pressurized load w is obtained.

[0053]

By applying the present invention to the correction of bending, there is a high possibility that correction can be performed with high accuracy with respect to the target amount of plastic deformation in one correction trial, and an average of three correction trials is performed. Thus, the correction can be performed with high accuracy for the target amount of plastic deformation.

[Brief description of the drawings]

FIG. 1 is a flowchart of processing of a bending correction load calculation method.

FIG. 2 is an explanatory diagram of a correction position and a plastic deformation amount.

FIG. 3 is an explanatory diagram of a relationship between a maximum load and a plastic deformation amount at the time of straightening a material to be straightened based on an example of a result of applying the present invention.

FIG. 4 is an explanatory diagram of a relationship when a logarithm of a maximum load and a logarithm of a plastic deformation amount at the time of correcting a material to be corrected based on an example of a result of applying the present invention.

FIG. 5 is an explanatory diagram showing the relationship between the cumulative amount of plastic deformation in the same direction as the pressing direction and the maximum pressing load in the first pressing when one pressing position of the material to be corrected is pressed six times. FIG.

FIG. 6 is a graph showing the relationship between the cumulative plastic deformation in the direction opposite to the pressing direction and the maximum pressing load in the first pressing with the cumulative plastic deformation before the pressing when the pressing direction is changed for the first time being 0; FIG.

FIG. 7 is an explanatory diagram of a conventional method.

[Explanation of symbols]

 1 ... Correction data input method, 2 ... Target maximum load output method, 3 ... Correction history storage method, 4 ... Processing characteristic calculation method, 5 ... Target maximum load output method.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masanori Kondo 1070 Ma, Hitachinaka City, Ibaraki Prefecture Inside the Mito Plant of Hitachi, Ltd. (72) Inventor Masahiro Nagai 1070 Ma, Hitachinaka City, Hitachinaka City, Ibaraki Prefecture Hitachi, Ltd. Inside Mito Factory (72) Inventor Mitsuru Yamada 1070 Ma, Hitachinaka City, Ibaraki Pref. Mito Factory Hitachi, Ltd. (56) References JP-A-6-277760 (JP, A) JP-A-54-135659 ( JP, A) JP-A-55-117520 (JP, A) JP-A-2-192820 (JP, A) JP-A-63-199026 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B21D 3/00-3/16

Claims (11)

(57) [Claims] 1. A symbol for identifying an individual material to be corrected, a correction position, a pressing direction, a plastic deformation amount required for correction, a maximum pressing load and a plastic deformation amount at the time of performing correction, and a correction value at the time of correction. In the bending correction load calculating method for outputting the target maximum load, a correction history storage for storing a maximum pressing load at the time of correction, a plastic deformation amount, a symbol for identifying an individual, a correction position, a correction frequency, and a pressing direction; Calculate the relational expression between the maximum pressurizing load and the plastic deformation by taking the logarithm of the maximum pressurizing load and the amount of plastic deformation at the time of straightening and calculating the regression line to calculate the target maximum load at the time of straightening. A bending straightening load calculation method characterized by the following. 2. The method according to claim 1, wherein the maximum pressurizing load and the plastic deformation amount in correcting the stored current straightening position of the current material to be corrected are both plural. A bending correction load calculation method that calculates the relational expression between the maximum applied load and the plastic deformation amount by taking the logarithm of each deformation amount and obtaining a regression line. 3. The method according to claim 1, wherein when either of the stored maximum pressurizing load and the amount of plastic deformation in the correction of the current correction position of the stored current material to be corrected is less than two, the stored correction is performed. The relationship between the maximum pressurized load and the amount of plastic deformation by taking the logarithm of each of the maximum pressurized load and the amount of plastic deformation during correction at one or more correction positions of one or more materials to be corrected and obtaining a regression line A straightening load calculation method for calculating the equation. 4. The method according to claim 3, wherein when the stored current maximum correction load and the plastic deformation amount at the current correction position of the stored current material to be corrected are both present, the stored current material to be corrected is stored. Using the maximum pressurizing load at the time of correction at the current straightening position and the amount of plastic deformation at the time of correction, the relational expression between the maximum pressurizing load at correction and the amount of plastic deformation calculated at the same time is translated and the current correction position of the current material to be corrected is A bending straightening load calculation method for calculating a relational expression between the maximum pressurizing load and the amount of plastic deformation in straightening. 5. The method according to claim 1, wherein there is data of a pressing direction in the stored correction of the current correction position of the current material to be corrected which is opposite to the input pressing direction. The relational expression between the maximum pressurized load and the amount of plastic deformation by taking the logarithm of each of the maximum pressurized load and the amount of plastic deformation in the correction of the stored current straightening position of the current material to be corrected and obtaining a regression line and moving in parallel. To calculate the straightening load. 6. The pressurizing direction stored in the stored pressurized material according to claim 1, wherein the last stored pressurizing direction in the correction of the current corrective position of the current material to be corrected is opposite to the input pressurizing direction, When at least one of the stored pressing directions in the correction of the current correction position of the current material to be corrected other than the last stored pressing direction is the same as the input pressing direction, the stored pressing direction is stored. Of the pressing directions in the correction of the current correction position of the current material to be corrected, which are the same as the input pressing direction and the last stored direction, the maximum pressing load and the amount of plastic deformation stored simultaneously with the stored direction. Are combined into a first point, and among the stored pressing directions in the correction of the current correction position of the current material to be corrected, which is the same as the input pressing direction and lastly stored, The later Based on the result of the calculation using all of the load and the amount of plastic deformation, the point obtained by translating the first point is defined as the second point, and the logarithm of each component is calculated to obtain a regression line. A straightening load calculating method for calculating a relational expression between the maximum pressure load and the amount of plastic deformation. 7. A method for straightening a long material using one or a plurality of the methods according to claim 1. 8. A long material bending straightening apparatus using one or a plurality of the methods according to claim 1. 9. An apparatus for straightening an elevator guide rail using one or a plurality of methods according to claim 1. 10. A bending apparatus using one or a plurality of methods according to claim 1. 11. A tension-compression processing apparatus using one or a plurality of methods according to claim 1.