JPH0414285B2 - - Google Patents

Description

[Detailed description of the invention]

[Effects of the Invention] The present invention relates to a method for bending a plate-like member having elasticity and plasticity, such as a steel plate. [Background of the Invention] For example, a fold line 1 is formed on a steel plate 11 shown in FIG.
1 and 12 to form a shallow box-shaped member 14, as shown in FIG. The deing leaf 21 is rotated in the direction of arrow a and bent. However, as shown in Figure 4, after bending the holding leaf to the target angle α ₀ (right angle in this example),
When the steel plate 11 is rotated back in the opposite direction of the arrow a, the steel plate 11 springs back to a bending angle α _b1 as shown in FIG. Here α _b1 > α ₀ . To detect the bending angle in such work, the technique disclosed in Japanese Patent Application Laid-Open No. 57-207803 is known, but the device is complicated and expensive. In order to solve these problems and easily detect the bending angle of a plate-shaped member with a simple device, a device shown in FIG. 6 can be considered. This device was created by the present inventors and is currently under separate application, and its outline will be described below. The non-contact distance sensor 22 is attached to the holding leaf 21 at a right angle, and the angle θ between the steel plate 11 and the holding leaf 21 is
The bending angle α ₁ ′ of the steel plate 11 from the angle of the holding leaf 21 can be calculated as α ₁ ′=β ₁ ′−θ =β ₁ ′ ^{−tan −1 I} /a. be able to. As shown in Figure 7, holding leaf 2
The bending angle β ₁ of 1 is detected by the encoder 23 and fed back to the automatic control device 24 of the folding device. In FIG. 7, in order to bend the steel plate 11 to the target angle α ₀ , the steel plate 11 is bent to β ₁ by the holding leaf 21 in consideration of spring back. After the first bending process is completed, the holding leaf 21 moves back, and as shown in FIG. 8, the sensor 22 detects that the distance between the steel plate 11 and the holding leaf 21 is l,
1, the angle α ₁ ' of the steel plate 11 after spring back is determined from the rotation angle β' of the steel plate 11. Compare α ₀ and α ₁ ′, and if the bending is insufficient, proceed to the process shown in FIG. 9. Taking into account the correction for the springback angle α ₁ ' - α ₁ , the holding leaf 21 reworks the steel plate up to β _2. After the bending is completed, the holding leaf 21 retreats, detects the bending angle of the steel plate 11, and detects insufficient bending. In the case of,
The same processing is repeated, and when the bending angle α ₂ ' falls within the tolerance, the bending is completed (FIG. 10). Figures 11 and 12 show the fourth
FIG. 6 is an explanatory diagram showing a finishing process following the process (first bending) of FIGS. In the conventional technology, as described above, the bending process is repeated multiple times to finally achieve the target angle α ₀ . At this time, if it is bent too much than the target angle α ₀ ,
Since the steel plate must be removed from the bending device and corrected, a great deal of effort and time is expended, so the bending process is repeated several times to avoid excessive bending. Therefore, it is desirable to proceed from the target angle α ₀ to a bending angle within the allowable error range in as few times as possible under the restriction of “not bending too much.” However, the steel plate that is the workpiece is generally not an isotropic material, but has directionality related to its rolling direction. In the steel plate 11 rolled in the direction of the arrow 10 shown in FIG. 3, 12 is a bending line perpendicular to the rolling direction;
13 is a parallel bending line. As shown in FIGS. 4 and 5, the bending angle α _b1 after the spring back after the first bending of the bending line 12 perpendicular to the rolling direction (hereinafter referred to as the perpendicular bending line) is The bending angle after spring back when the bending line 13 parallel to the rolling direction (hereinafter referred to as parallel bending line) is subjected to the first bending process under the same conditions as shown in FIGS. 13 and 14. α _c1 becomes smaller. Therefore, in the subsequent step, as shown in Fig. 15, at an angle α _c2 such that α _b2 < α _c2 ,

[That is, the second bending angle when bending the right-angled bending line 12 (see Figure 11) α _b2 ] Second
Perform round bending. In the conventional technology, as explained above, the rotation angle of the holding leaf 21 for the next bending process is determined based on the first bending result, keeping in mind the rolling direction of the steel plate 11 as the material. We will proceed with the work. Such work requires a high degree of training on the part of the operator, requires a great deal of time and effort, and is likely to result in human error. [Object of the invention] The present invention has been made in view of the above circumstances, and
The characteristics of the steel plate are stored in the automatic control mechanism, and the rolling direction of the steel plate is automatically determined based on this stored data, and the appropriate first bending angle (rotation angle of the holding leaf) and next bending angle are determined. The purpose of this invention is to provide a method that allows bending to be performed with high efficiency and without the risk of human error. [Summary of the Invention] In order to achieve the above object, the processing method of the present invention includes means for gripping a plate-shaped member as a workpiece;
A holding leaf that rotates to bend the plate-like member while closely contacting the gripped plate-like member; a means for detecting the rotation angle of the holding leaf; and a means for detecting the rotation angle of the holding leaf when the holding leaf is separated from the plate-like member. means for detecting that the interval has reached a predetermined value, and an automatic calculation device that calculates and records the amount of deflection and springback of the plate-like member when given the output signals of both of the detection means. The characteristic values of elastic deformation and plastic deformation of the plate-like member are recorded, and the characteristic values of elastic deformation and plastic deformation when the unprocessed plate-like member is subjected to the first bending process are memorized. By comparing with the characteristic values, the relationship between the direction of the bending process and the rolling direction of the plate-shaped member is determined, and the holding leaf rotation in the next bending process is determined so as to obtain plastic deformation close to the bending target angle. It is characterized by calculating the moving angle. [Embodiment of the Invention] Next, an embodiment of the present invention will be described with reference to FIG. In execution block A in the algorithm shown in this figure, a target bending angle α ₀ is set as initial bending data β ₁ and trial bending is performed. This is because steel plates have a property called springback.
This is because there is no risk of over-bending by performing the initial bending at the target angle α ₀ . Here, the springback angle is calculated as follows: after the steel plate 11 is bent at an angle α ₁ by the rotation angle β ₁ of the holding leaf 21 shown in FIG.
The sensor 22 detects that the distance between the holding leaf 21 and the holding leaf 21 becomes l, and the springback angle of the steel plate 11 can be determined from the rotation angle β ₁ ' of the holding leaf 21 at this time. The calculation formula is as follows: If the angle of the steel plate 11 after springback is α ₁ ', and the distance from the center of rotation of the holding leaf 21 to the position where the sensor is attached is l, then springback angle = α ₁ ' −α ₁ =β ₁ ′−tan ⁻¹ I/a. In this way, the first bending can be performed absolutely safely, the characteristics of the steel plate can be grasped, analyzed, and the next process can be automatically controlled. That is, a steel plate is processed using blocks B, C, and D, and the steel plate bending angle α ₁ ' and springback angle S ₁ are determined.
Judgment block E determines whether or not a _correction bending of the initial springback angle S ₁ has been performed in the past with respect to the target angle _{α 0} . The final corrected bending data is retrieved from the storage area and substituted. If not, execution block I adds half the springback angle S _i-1 to the bending data β _i-1 and uses the result as new corrected bending data. Perform correction bending while preventing excessive bending in execution blocks J, K, and L. If bending is insufficient according to judgment blocks M and N, corrective bending is performed again from execution block I, and when the steel plate bending angle is within the allowable error. () If there is no history of correction bending in the past, that data is stored as the final bending processing data. () If you have a history of corrective bending in the past, correct your memory by taking the average with past data. In the unlikely event that it is bent too much, use the execution block P.
Displays an alarm. The data obtained by the algorithm shown in FIG. 1 is stored in association with the springback angle of the first bending for each target angle α ₀ . The above algorithm analyzes the bending characteristics of a steel plate during the process of bending the steel plate, and reflects the results in the next bending process, making it possible to reduce the number of bending processes and improve precision. Furthermore, if the bending angle data with respect to the rolling direction of the steel plate is used, when obtaining the corrected bending data in execution block I in the algorithm of FIG. 1, for example, in the case of a bending line perpendicular to the rolling direction, It is also possible to change the correction value for each rolling direction by subtracting 2/3・S _i-1 from β _i-1 , and in the case of parallel bending lines, subtracting 1/3・S _i-1. . The automatic calculation device shown in FIG. 7 has a function of storing the characteristics of the steel sheet, automatically determining the rolling direction of the steel sheet based on this stored data, and calculating the appropriate first bending angle and next bending angle. It will be ready on the 24th. Next, a different embodiment from the above will be described with reference to FIG. Execution block B' bends multiple pieces using the algorithm shown in Figure 1, and if the variance of the final bending data β ₁ is within the tolerance, the execution block executes the first bending data for the target bending angle α ₀ . Determine from the average value of β ₁ at D′. Execution block E' detects the bending angle after bending, and if judgment block F' determines that the steel plate bending angle is within the tolerance, execution block G' determines how the steel plate bending angle changes within the tolerance. Find out what's going on. In other words, an equation of a straight line that approximates the bending angle is determined from the processing history up to the bending process in question, and depending on the slope, it is possible to determine whether the bending angle tends to be larger or smaller, or randomly. The bending process data for the next process is corrected. As a method of correction, for example, there is a method of adding or subtracting a value of 1/2 of the slope of the straight line from the bending data. Next, processing is repeated until the number of processed sheets is completed according to judgment block K'. If the steel plate is outside the tolerance,
An alarm is displayed by execution block H', and if the bending is insufficient, correction bending is possible, so correction is made by execution block J'. Judgment block A' determines whether machining is complete. If not, execution block Repeat the same process from B′. The machining data obtained in the execution block D' of the algorithm shown in Figure 2 is classified and stored for each target bending angle and by the springback angle in the first bending process, and is used in the next bending process to increase the number of trial bends. can also be reduced. As described above, according to this embodiment, it is possible to bend steel plates that are considered to be of the same material in one step. In the embodiment described above (Fig. 2),
Even if there are variations in the physical properties (hardness, elasticity, plasticity) due to changes in the material of the steel plate or non-uniform springback properties due to the relationship with the rolling direction, the steel plate can be bent at a predetermined angle. In addition, the bending characteristics of the steel plate can be analyzed and bending processing data can be accumulated using the data obtained in the process of correcting the bending angle, and if the steel plate material is almost the same, the initial bending process can be used to It can be bent within ±0.2° of the specified bending angle. In addition, if the present invention is partially applied to the operation of a manually operated bending device, if the steel plate is taken out after bending and there is insufficient steel plate, it will be necessary to carry it in again, reprocess it, and re-inspect the angle. There will be no need. If applied to automatic level equipment, it becomes unnecessary to input numerical control data for bending, and it is possible to eliminate inspection and correction work for completed steel plates. Furthermore, when it is necessary to specify a bending angle in the bending direction, such as in the case of a reinforcing material, it is possible to detect the angle of the rolling direction with respect to the bending line, thereby improving reliability. [Effects of the Invention] As detailed above, according to the method of the present invention, the characteristics of the steel plate are stored in the automatic control mechanism, and the rolling direction of the steel plate is automatically determined based on this stored data. The first bending angle (rotation angle of the holding leaf) and the next bending angle are calculated, and the bending process can be performed with high efficiency and without the risk of human error, which is an excellent practical effect.

[Brief explanation of drawings]

1 and 2 are block diagrams each showing an algorithm in an embodiment of the processing method of the present invention. FIG. 3 is an explanatory diagram of a steel plate bending operation, and FIGS. 4 and 5 are initial bending operation process diagrams for explaining springback in the steel plate bending operation. FIG. 6 is a diagram illustrating the configuration of a known bending machine, and FIGS. 7 to 10 are diagrams illustrating the operating process. FIGS. 11 to 16 are explanatory diagrams of the bending process of a plate-shaped member having springback properties. DESCRIPTION OF SYMBOLS 10...Rolling direction, 11... Steel plate, 12... Bending line perpendicular to the rolling direction, 13... Bending line parallel to the rolling direction, 20... Bending device, 21... Holding leaf, 22... Sensor , 23... encoder, 24... automatic control device for bending equipment, 25...
...Steel plate holder.

Claims (1)

[Scope of Claims] 1. A means for gripping a plate-shaped member as a workpiece;
A holding leaf that rotates to bend the plate-like member while closely contacting the gripped plate-like member, a means for detecting a rotation angle of the holding leaf, and a means for detecting when the holding leaf is separated from the plate-like member. The angle of the plate member after spring back is determined from the rotation angle of the holding leaf at that time, and the angle of the plate member after spring back is obtained by subtracting a preset target angle from this angle. Equipped with automatic calculation means that calculates and stores the characteristic values of elastic deformation and plastic deformation of the plate-like member from the amount of spring back by subtracting it from the rotation angle at the time the plate-like member is bent by the holding leaf. The automatic calculation means compares the elastic deformation and plastic deformation when the unprocessed plate-shaped member is subjected to the first bending process with the stored values, and determines the direction of the bending process and the rolling direction of the plate-shaped member. A bending angle detection/correction/processing method characterized in that the holding leaf rotation angle in the next bending process is calculated so as to obtain plastic deformation close to the bending target angle. 2. The above-mentioned first bending process is performed by controlling the amount of rotation of the holding leaf based on the average value of the memorized characteristic values so as to obtain plastic deformation close to the target value. Bending angle detection/correction/correction according to claim 1 characterized in
Processing method.