JP2001105027A - Method for straightening bed of bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for straightening the bend of a bar by which high accuracy of straightening is attained with a small number of times of straightening without depending on the manual operating of a skilled technician and which is easily automated. SOLUTION: A required forcing angle λ1 for straightening is calculated from the target straightening angle β0 and reference straightening curve A1 of a work and the bend is straightened by forcing a bent part. After that straightening, an actual straightening angle β1 is determined from the difference (α1-α0) between the forcing angle α1 when a measuring load (w) within the region of elastic deformation is loaded on the bend part of the work and the forcing angle α0 by the same measuring load (w) before straightening the work. When the actual straightening angle β1 does not reach the target straightening angle β0, a corrected reference straightening curve A2 is determined by correcting the reference straightening curve A1, a new straightening/forcing angle γ2 is calculated based on this corrected straightening curve A2 and straightening is again executed. This procedure is successively repeated till the straightening angle reaches the target straightenint angle β0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for straightening a bar. The rod material referred to herein includes a screw shaft having a screw groove and the like.

[0002]

2. Description of the Related Art The bending of a long bar is corrected by applying a load (correcting load) in a direction opposite to the bending direction to a bent portion of the bar. In this case, the correction conditions such as the magnitude of the correction load to be applied vary depending on the shaft diameter of the bar to be corrected, the correction span, and in the case of a screw shaft, the shape of the thread groove and the like.

[0003] Therefore, conventionally, bending correction has been performed using a load determined by the correction results for each bar specification.

[0004]

However, in such a straightening method, it is necessary to create different straightening conditions every time the specifications of the bar are different, and a new straightening condition is required every time a new type of bar is straightened. I have to decide. Further, when there is a groove only in a part of the bar to be corrected, the condition is further complicated. Therefore, especially in the case of multi-kind small lot products, the time required for setting the correction conditions is enormous,
There is a problem that it is difficult to automate the correction work, and in the past, it was necessary to rely on manual correction by a skilled technician.

Accordingly, the present invention has been made in view of such unresolved problems of the prior art, and is intended to provide an automated method capable of obtaining a high correction accuracy with a small number of corrections without manual work of a skilled technician. It is an object of the present invention to provide a method of straightening a bar material easily.

[0006]

Means for Solving the Problems To achieve the above object,
First, a method for straightening a bar (work) according to the present invention
In advance, the correction push-in angle of the bent bar and its
Correction reference curve A based on the relationship data with the plastic deformation angle₁Ask for
Before performing straightening of the work,
Apply a measured load w within the elastic range to the barn section and
Elastic indentation angle α when elastically deformed₀By measuring
In advance, the target plastic deformation angle of the work (target correction angle)
β₀And the correction reference curve A₁And the required correction push
Angle γ₁Is calculated and the correction pushing angle γ₁Bend until
To correct the bending of the work by pushing the
Immediately after, the measured load w is applied again to the bent portion of the work.
Lever pushing angle α₁The same before the work straightening
Pushing angle α due to measured load w₀Difference (α₁−α₀)
From the actual correction angle β₁And the actual correction angle
β₁Is the target correction angle β₀If not reached, the correction reference music
Line A ₁To correct the corrected standard curve A_TwoThis repair
Correction standard curve A_TwoNew correction pushing angle γ based on_Two
Is calculated and the correction is performed again. ₀
It repeats until reaching.

[0007] According to the method of straightening a bar according to the present invention,
Conventionally, while the straightening is performed while controlling the load applied to the straightened portion to adjust the pushing amount, the angle at which the straightened bar is bent is controlled as described above. Therefore, it is hardly affected by the shaft diameter of the bar to be straightened, the size of the straightening span, and the shape of the screw in the case of a screw shaft. Is possible.

Conventionally, it took time to set correction conditions for each specification. However, since it is not necessary, it is possible to realize automatic correction even for a large variety of small lot products.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an angle when a work is pushed by a straightening head, that is, a “corrected pushing angle γ”, and FIG. 2 is a diagram for obtaining a straightening reference line A from actual measurement data of a straightening pushing angle γ and a plastic deformation angle β. FIG. 3 is a schematic diagram, and FIG. 3 is a graph illustrating a method of calculating the correction indentation angle γ based on the correction reference line A. FIG. 4 illustrates a relationship between the correction indentation angle and the correction load, and a method of calculating the plastic deformation angle during the correction. FIG.

Although not shown in this embodiment,
The straightening of the bar of the present invention can be automatically performed using a straightening device. The bending straightening device is a straightening cylinder for applying a straightening load to a bent portion of a work, a means for detecting a straightening load to be applied, a means for detecting a bending angle of a work during straightening, a means for controlling a position of a straightening cylinder, An arithmetic unit for calculating a control position of the straightening cylinder based on signals from the straightening load detecting means and the bending angle detecting means is provided.

A bar (work) having a bent portion to be corrected is first measured at a plurality of positions in the longitudinal direction while supporting and rotating both ends, and before bending, a bending correction position, a correction phase, and a correction amount. (Angle) is calculated. Thereafter, the work is moved to a correction position, and a high-precision bending correction is performed based on the calculated correction amount (angle).
It is not necessary to consider the specifications of the thread groove for the diameter of the bar and the screw shaft.

The details of the correction procedure will be described. (1) Preparation of “correction reference line” as a preparation stage: In the method of correcting the bending of a bar according to the present invention, a bending correction is experimentally performed in advance, and the correction result, that is, “correction pushing angle γ” (FIG. 1) and the angle of plastic deformation, that is, the data of “plastic deformation angle β”. For example, FIG.
Is based on the experimental data obtained for each of the screw shafts having a diameter of 10 mm and a diameter of 15 mm.
Is plotted on a diagram representing the relationship with. From this, it can be seen that there is no difference due to the specification of the work. Such data is not limited to only experimental data, but can be accumulated and learned in actual bending correction work to further improve correction accuracy.

From these accumulated data, only data having the smallest correction indentation angle γ with respect to the plastic deformation angle β are sampled, and the relationship of “indentation angle” ── “plastic deformation angle” is expressed from the sampled data. By obtaining the approximate curve, the "correction reference formula A ₁ " as shown in FIG.
(Hereinafter also referred to as a correction curve). (2) Pre-correction process: Before performing correction of the work, a measured load w within the elastic range is applied to the bent portion of the work by applying the measured load w, and the elastic pressing angle α when the work is elastically deformed in the correction direction.
Measure ₀ .

Further, the bending angle of the bent portion is detected by detecting means.
Measure and correct target angle β₀Ask for. And shown in FIG.
Thus, the correction curve A₁And the target correction angle β₀
Correction pushing angle γ corresponding to₁(Target correction angle β₀Get
Is the minimum corrective indentation angle necessary for the calculation. Goal
Correction angle β₀And minimum correction indentation angle γ₁Correction corresponding to
Positive curve A₁The upper point is P₀It is. (3) Straightening process: Obtained straightening angle γ₁By correction
Do the positive. That is, a straightening head is used at the bent part of the work.
Correction push angle γ₁Until it reaches plasticity
Deform. (4) Verification of correction results: After this first correction,
Actual correction angle β, which is the actual amount of plastic deformation₁Ask for. Sand
In other words, as shown in FIG.
Correction started because angle γ and correction load W are in a proportional relationship
A bullet with a specific load (the measured load) w in the previous elastic region
Push-in angle α₀And measurement push by the same load w after straightening
Included angle α ₁(Actual value) and the difference (α₁−α₀Take)
The actual plastic correction angle β₁= (Α₁−α₀)
It is possible to (5) Creation of a modified "correction reference line" for the second correction:
Actual correction angle β measured after the first correction₁Is the target correction
Regular angle β₀If less than the above, as shown in FIG.
Positive curve A₁Is shifted in the pushing direction, and the first correction is performed.
Point P that is a positive result₁Correction curve A corrected so that_Two
Get. (6) Pre-process of secondary correction: target correction angle β₀And a new correction
Positive curve A_TwoFrom equation A_TwoUpper point P_Two, And this point P
_TwoCorrection pushing angle γ corresponding to_Two(Target correction angle β₀Get
Is the second corrective indentation angle required for
(See FIG. 3). (7) Secondary straightening step: Second straightening push angle obtained
γ_TwoTo perform the correction again. That is, the first correction
Apply the straightening head to the same bend that was given and press in straightening
Angle γ_TwoUntil it reaches. (8) Verification of secondary correction result: after this second correction
The actual correction angle β, which is the actual amount of plastic deformation._TwoAnd above
Find in the same way. That is, as shown in FIG.
The specific load in the elastic region before the first straightening starts
Weight) Push angle α by w₀And the same measured load w after correction
Angle α_TwoDifference (α_Two−α₀Take)
The actual plastic correction angle β_Two= (Α_Two−α₀)
You. (9) Creation of a modified “correction reference line” for the third correction:
Actual correction angle β measured after the second correction_TwoIs the target correction
Regular angle β₀If less than the above, as shown in FIG.
Positive curve A_TwoIs shifted in the pushing direction, and the second correction is performed.
Point P that is a positive result_ThreeCorrection curve A corrected so that_Three
And the third correction indentation angle (γ_Three) And ask again
Perform various corrections. (10) The same operation is performed with the target correction angle β₀Until you reach
Repeat.

(Example) Using a screw shaft having a diameter of 10 mm as a work, bending was corrected by the method of the present invention. The data shown in FIG. 5 is used as the relation data between the correction indentation angle of the work and its plastic deformation angle, and the target correction angle (β ₀ ) is 2.9.
The curve was corrected at 0 × 10 ⁻⁴ rad.

FIG. 6 shows the result. It can be seen that the correction was very close to the target with the two corrections.

[0017]

As described above, according to the present invention, the straightening section is pushed in while controlling the bending angle of the work by using the bending straightening data accumulated in advance, so that the straightened rod material is used. In the case of the shaft diameter, straightening span, and screw shaft, there is an effect that high-precision automatic straightening can be realized under the same straightening conditions irrespective of the rod material specifications such as the thread shape.

[Brief description of the drawings]

FIG. 1 is a diagram showing “correction pushing angle γ”.

FIG. 2 is a schematic diagram for obtaining a correction reference line A from actual measurement data of a correction indentation angle γ and a plastic deformation angle β.

FIG. 3 is a graph illustrating a method of calculating a correction pushing angle γ based on a correction reference line A.

FIG. 4 is a diagram illustrating a relationship between a correction pushing angle and a correction load and a method of calculating a plastic deformation angle during correction.

FIG. 5 is a graph in which relation data between the indentation angle and the plastic deformation angle are accumulated.

FIG. 6 is a graph showing the results of a bar bending correction experiment using the method of the present invention.

[Explanation of symbols]

A ₁ straightening reference curve A ₂ corrected correction reference curve beta ₀ target correction angle beta ₁ actual correction angle gamma ₁ straightening indentation angle gamma ₂ new corrective pushing angle

Claims (1)

[Claims] 1. A bar material (work) having a bend in advance
From the data on the relationship between the indentation angle and the plastic deformation angle
Positive reference curve A₁And work correction
Before, the measured load w within the elastic range is applied to the bent portion of the work.
Indentation when elastic deformation is applied in the correction direction by applying force
Angle α₀, And the target plastic deformation angle (target correction angle) β₀And said
Correction reference curve A₁And the required correction pushing angle γ₁Is calculated
Out, and its correction inset angle γ₁Push in the bend until
Correcting the bending of the work, and after the correction, applying the measured load w again to the bent portion of the work.
Load and push-in angle α₁Before the work straightening
Indentation angle α with the same measured load w₀Difference (α₁−
α₀) From the actual correction angle β₁And the actual correction angle β₁Is the target correction angle β₀Must reach
The correction reference curve A ₁Correct the corrected straightening reference curve
A_TwoAnd the corrected correction reference curve A_TwoBased on new
Correction push angle γ_TwoThe process of calculating and correcting again
Is the target correction angle β₀The feature is to repeat sequentially until it reaches
The straightening method of the bar material.