JP2723349B2 - Automatic long straightening device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) For example, a long object straightening device which corrects the bending of a long metal object such as a bar, a shaft, and a guide rail for an elevator to increase straightness. Related to the device.

(Prior Art) In general, when it is necessary to obtain a desired straightness for a long metal object such as an elevator guide rail, it is measured whether the straightness is within an allowable range, and a deviation exceeding the allowable value is measured. Needs to be corrected by a straightening press or the like.

FIG. 7 shows a conventional correction device of this type.

FIG. 7 is a perspective view of a hydraulic press-type automatic long straightening device for correcting bending of a long metal object (hereinafter referred to as a work).

In FIG. 7, a measuring instrument 1 for measuring the straightness of a work
On one side of the rail 2 on which the vehicle travels, a plurality of transport rollers 3 are installed at appropriate locations such that the rotation axis of the transport roller 3 is perpendicular to the rail 2. A positioning roller 5 for positioning the work 4 at the time of measurement is provided near the transport roller 3. Further, between a plurality of transport rollers 3 installed on one side of the rail 2, a roll table 6 for rotating the work 4 by 90 ° is installed.

A three-point hydraulic press 7 is provided at one end of the row in which the transport rollers 3 and the roll table 6 are arranged. Further, a plurality of transport rollers 8 for sequentially transporting the work 4 sent from the transport rollers 3 and pressed by the hydraulic press 7 are provided. Similarly to the transport roller 3, a roll table 9 for rotating the work 4 by 90 ° is provided between the transport rollers 8. Here, in order to move the work 4 on a straight line, the conveying roller 3, the horizontal turning table 6, the press position of the correction press 7, the conveying roller 8, and the horizontal turning table 9 are installed on a straight line.

Then, the work 4 is placed on the transport roller 3 and the transport roller 3 is rotated to transport the work 4 to a predetermined position. Next, the work 4 stopped at a predetermined position is positioned by the positioning roller 5 at a position to be measured. After the work 4 is positioned at a predetermined position, the straightness measuring instrument 1 measures the bending of the work 4 while moving on the rail 2. This measurement data is input to an arithmetic unit in the control panel 10. When the measurement is completed as described above, the transport roller 3 rotates again, and the work 4 is transported to the correction press 7.

Next, based on the measurement data from the arithmetic unit 12, the control unit
The work 11 is conveyed by controlling the conveying rollers 3 and 8.
The work 4 is transported until the straightening point of the work 4 reaches the position of the straightening press 7, and the work 4 is moved by the hydraulic press 7.
Correction is performed.

The work 4 that has been sequentially corrected is conveyed by conveying rollers 8 installed on the opposite side of the hydraulic press 7. When the straightening is completed, the transport rollers 3 and 8 rotate in reverse, the workpiece 4 is transported to the shape measuring position, and the shape of the workpiece 4 is measured again. At this time, if there is still a deviation beyond the allowable range even though the correction has been performed once, the work 4 is transported by the transport rollers 3 and 8 in the same manner as described above, and the hydraulic press 7 performs the correction again. .

If all the values are within the allowable range, the correction in one direction is completed, the work 4 is rotated by 90 °, and the correction operation is performed again from the shape measurement.

When the correction in two directions is completed in this way, the work 4
Is transported by the transport rollers 3 and 8, and the correction of the work 4 is completed.

Here, a method of determining a correction point and a correction amount in a conventional correction device will be described with reference to FIG.

FIG. 8 shows the shape of the work 4 whose straightness has been measured, and this work 4 is placed in an xy coordinate system. At this time, the measurement point of the shape measurement is taken on the x-axis, and the absolute position of the workpiece 4 in the deviation direction is taken on the y-axis.

Here, the work 4 is a straight line y in the coordinate system in FIG.
Consider correction to be closest to = ax + b. Now, if the correction amount at the measurement point x _i is defined as [delta] _i,
Absolute position after correction at point x _i only in terms Correction x _i becomes (y _i -δ _i) in FIG. 8 in a coordinate system.

In this case, the work is straightened by a hydraulic press including two anvils 14 and a straightening punch 15 (No. 9).
Figure).

Next, consider the impact on the x _i points by straightening at different points x _j and x _i. At this time, assuming that the correction amount at the point x _j is δ _j , the correction amount per unit length of the work 4 is (δ _j / l). Thus, the influence of the deformation amount at the point x _i straightening at a point x _j is | a _{· δ i / l | x i} -x j. Here, 1 indicates half the length of the anvil span as shown in FIG.

The effect of the work 4 at the point x _i based on the correction deformation at all the sampling points is Σ | x _i −x _j | · δ _i / l, and the absolute position of the work 4 at the point x _i after the correction of all points is , Y = y _i + Σ | x _i −x _j | · δ _i / l. Δ _i set so that the value of this equation is above y = ax + b is the correction amount at each point x _i .

Based on the above, work 4 after correction at each point
Is determined by the least squares method, and δ, a, b that minimizes this error are calculated to determine the correction amount and correction point.

(Problems to be Solved by the Invention) In a conventional automatic long object straightening apparatus using a method of determining a correction point by the least squares method, as a criterion for determining a correction point,
Only the deviation amount between the actual work shape and the reference straight line obtained by the least square method was used, and as shown in FIG. 10, a position where the deviation amount was large was determined as a correction point (No. 10).
Figure). Therefore, for example, a workpiece having a shape in which a portion having a large curvature is separated from a portion having a large deviation amount, or a work having a shape in which a portion having a large curvature approaches and a portion having a large deviation amount exists in another position ( 6a and 6b), it is difficult to determine the position of the correction point optimally, the number of correction points increases, and the correction takes time. There was a point. Generally, the work has a curvature and a distance between inflection points as shown in FIG.
The conventional automatic straightening device does not consider these curvatures and the distance between inflection points.

The present invention has been made in order to solve the above-described drawbacks, and has been made in consideration of not only the amount of deviation of a long metal object from a reference straight line but also the curvature and the distance between inflection points. It is an object of the present invention to provide a long object automatic straightening device capable of determining the straightening time and shortening the straightening time.

[Configuration of the invention]

(Means for Solving the Problems) The present invention provides a three-point hydraulic press for correcting the bending of a long metal object, a transport roller for moving the long metal object, and operation of the hydraulic press and the transport roller. And a measuring device that measures the shape of the long metal object at each measurement point, and at least a curvature or inflection at each measurement point of the long metal object based on shape data from the measuring device. A computing device for calculating various displacement factors including any of the point-to-point distances, and inference for determining the optimal correction point position of the long metal object using fuzzy logic based on various displacement factors from the computing device And a device for automatically correcting a long object.

(Operation) According to the present invention, based on shape data from a measuring instrument,
Since the calculation device calculates various displacement factors including at least either the curvature or the distance between inflection points at each measurement point, and the inference device determined the optimal correction point using fuzzy theory based on the various displacement factors, Unnecessary correction points can be reduced, which makes the determination of correction points more appropriate.

(Example) Hereinafter, an example of the present invention is described with reference to drawings.

1 to 6 are views showing an embodiment of an automatic straightening device for a long object according to the present invention. The appearance of the automatic long object straightening device is the same as that of the conventional device shown in FIG. Further, the same parts as those of the conventional device are denoted by the same reference numerals, and detailed description is omitted.

FIG. 1 shows a schematic diagram of a control circuit of the automatic long straightening device. In FIG. 1, a straightness measuring device 1 for measuring the straightness of a work, a three-point hydraulic press 7 for straightening the bend of the work 4, and a rollover are provided beside the work 4 conveyed by conveying rollers 3 and 8. Tables 6, 9 are provided.

In addition, straightness measuring instrument 1, transport rollers 3,8, rollover tables 6,9,
And the three-point hydraulic press 7 are each connected to a control device 11, and the control device 11 further comprises an arithmetic device 12 and an inference device.
13 are sequentially connected. The controller 11 receives a signal from the straightness measuring device 1 and controls the operation of the transport rollers 3 and 8, the hydraulic press 7, and the roll tables 6 and 9. The functions of the arithmetic unit 12 and the inference unit 13 will be described later. The control device 11, the arithmetic device 12, and the inference device 13 are housed in the control panel 10.

 Next, the operation of the present embodiment will be described with reference to FIG.

As with the conventional device, first, work 4
Is measured (S1), and if there is a part outside the allowable range (S1)
2) The data is transferred from the straightness measuring instrument 1 to the arithmetic unit 12 via the control unit 11. The arithmetic unit 12 calculates each displacement factor such as the amount of deviation from the reference straight line, the curvature, and the distance between inflection points for each measurement point (S3), and transfers it to the inference unit 13.
In the inference device 13, each of these displacement factors is
3A to 3C, a fuzzy quantity represented by a membership function as shown in FIGS. 3A to 3C, and a comparison is made using fuzzy theory (S4). From a correction priority function as shown in FIGS. 4A and 4B, The correction priority at each measurement point is obtained.

Here, a method of determining a correction point using fuzzy theory will be described in detail.

First, as described above, the displacement device such as the amount of deviation from the reference straight line at each measurement point, the curvature, the distance between inflection points, and the like is obtained from the work shape data by the arithmetic unit 12. Then, these values are obtained by the inference device 13 from the membership functions shown in FIGS. 3a to 3c to obtain the high degree, medium degree and low degree of each factor.

For example, the amount of deviation from a reference straight line at a certain measurement point,
It is assumed that the values of the curvature and the distance between the inflection points are indicated by broken lines in FIGS. 3a, 3b, and 3c. In this case, 3a
In the figure, the medium degree is 1.0, and the high degree and the low degree are 0.5. In FIG. 3b, the high degree is 0.8, the medium degree and the low degree are 0.3 and 0.2, respectively. Further, in FIG. 3c, the medium degree is 1.0, the low degree and the high degree are
0.5.

Next, by applying these values to an output function as shown in FIG. 4a, an output function as shown in FIG. 4b is obtained.
That is, in FIGS. 3a to 3c, the minimum value of the high degree is 0.5, the minimum value of the medium degree is 0.3, and the minimum value of the low degree is 0.2. An output function as shown in the figure is obtained.

Next, the position of the center of gravity g is determined by the output function of FIG. 4b, and the horizontal axis component of the position of the center of gravity is the correction priority.

Perform the above operation for each measurement point, and
Obtain the output function shown in Figure 4b.

And the measurement point with the highest correction priority, that is, the center of gravity g
Is determined as the optimum correction point (S5).

Next, the arithmetic unit 12 simulates the shape after correcting the optimum correction point once, and at the same time, calculates the actual pushing amount of the correction press 7 by predicting the springback amount from the material characteristics (S6).

The method for determining the correction amount will be described below. First, linear regression is performed from the workpiece shape near the correction position, and a target straight line as shown in FIG. 5A is drawn. Then, the deviation amount between the target shape and the work shape near the correction position is taken as the area,
The work deformation amount at which this area is minimized is determined as the correction amount at this correction position (FIG. 5B). Further, the actual pushing amount (stroke) of the straightening press 7 is determined by estimating the springback amount of the work 4 from the straightening amount calculated from the material characteristics.

In this case, if the shift amounts of all the measurement points of the long metal object after the simulation fall within the allowable range, the determination of the correction point and the correction amount is completed.

On the other hand, if not within the allowable range, the deviation amount, the curvature,
Each displacement factor of the distance between inflection points is calculated, and the above calculation is repeated to obtain a second optimum correction point. Furthermore, this second
The shape after correcting the optimum correction point by a predetermined amount is simulated, and it is determined whether or not the deviation amounts of all the measurement points are within an allowable range.

In this way, the above operation is repeated until the deviation amounts of all the measurement points fall within the allowable range, and the third, fourth,... Optimal correction points and their correction amounts are calculated (S7).

When the optimum correction point and correction amount are determined by the method described above, these data are transmitted from the arithmetic unit 12 to the control unit 11.
Is forwarded to Then, the control device 11 controls the conveying rollers 3, 8
, And the correction points of the work 4 are sequentially conveyed to the position of the correction press 7. Next, when the straightening point of the work 4 comes to the position of the straightening press 7, the control device 11 performs a predetermined pushing control to the straightening press 7 from the straightening amount calculated in advance from the material characteristics.

According to the present embodiment, as shown in FIGS. 6a and 6b, there is an effect that the number of correction points is reduced with respect to a work having a large curvature and a large deviation amount. For example, in the case of a work having a shape as shown in FIG. 6a, the conventional apparatus corrects three points indicated by arrows a, b, and c. However, the automatic correction apparatus according to the present invention corrects two points indicated by arrows a, c. It can be corrected well. In the case of a workpiece having a shape as shown in FIG. 6b, the conventional apparatus corrects three points indicated by arrows d, e, and f, but the automatic correction apparatus according to the present invention corrects two points indicated by arrows d, e.
It becomes possible to correct with high accuracy by correcting the location. Further, in the conventional apparatus, arrows b (FIG. 6a) and arrows f (6b
(Fig.)
As shown by the arrows b and f, a portion having a smooth shape before the correction is bent, and therefore, there is a disadvantage that the appearance is curved even if there is no problem in accuracy. However, such disadvantages can be overcome with the device according to the invention.

〔The invention's effect〕

As described above, according to the present invention, the optimal correction point is determined using fuzzy theory based on various displacement factors including at least either the curvature or the distance between inflection points, so that unnecessary correction points are reduced. Can be done. Therefore, the determination of the correction point is made more appropriate, and the correction time can be reduced.

[Brief description of the drawings]

1 to 6 are views showing an embodiment of an automatic straightening device for a long object according to the present invention. FIG. 1 is a schematic diagram of a control circuit thereof, and FIG. 2 is an operation of the automatic straightening device for a long object. Figure showing the 3a
FIGS. 3b and 3c show membership functions used in fuzzy theory, FIGS. 4a and 4b show membership functions for finding optimal correction points, FIG.
6 (a) and 6 (b) are explanatory diagrams used for determining the correction amount, FIGS. 6a and 6b are diagrams showing a work shape which produces the effect of reducing the correction point, and FIG. FIG. 8 is an external view of an automatic straightening device for a long object, FIG. 8 is an explanatory diagram showing a method for determining an optimum straightening point and a straightening amount of a conventional automatic straightening device for a long object, FIG. 9 is a schematic diagram showing a three-point hydraulic press, FIG. 10 is an explanatory view showing a conventional correction point determining method, and FIG. 11 is an explanatory view showing a curvature of a work and a distance between inflection points. 1: straightness measuring device, 3: transport roller, 4: work, 5:
Positioning roller, 6: rollover table, 7: 3-point hydraulic press,
8: conveying roller, 11: control device, 12: arithmetic device, 13: inference device.

Claims (2)

(57) [Claims] 1. A three-point hydraulic press for correcting the bending of a long metal object, a conveying roller for moving the long metal object, a control device for controlling operations of the hydraulic press and the conveying roller, A measuring instrument for measuring the shape of the long metal object for each measuring point, including at least either the curvature or the distance between inflection points at each measuring point of the long metal object based on the shape data from the measuring instrument. An arithmetic device for calculating various displacement factors, and an inference device for determining a position of an optimal correction point of the long metal object using fuzzy logic based on various displacement factors from the arithmetic device. Automatic straightening device for long objects. 2. An arithmetic unit simulates the shape of the metal long object corrected for the optimum correction point determined by the inference unit and determines a predetermined correction amount. When the simulation shape falls within an allowable range, the arithmetic unit determines the predetermined correction amount. 2. The apparatus for automatically correcting a long object according to claim 1, wherein the optimum correction point is output to a control device so as to correct the predetermined amount by a predetermined amount.