JP2001191121A - Control data preparation method for twisting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control data preparation method for twisting while enables application of twisting to a long size stock in a twisting angle differing along the axis by using a pair of dies rotating relatively each other around the axis of a long size stock. SOLUTION: A twisting angle ψ around the axis per unit length specified in the axial direction, that is, in the direction of a line of centroid, that is, a specific twisting angle around the axis in the direction of a line of centriod is calculated based on shape data. A distribution curve 71 showing the variation in the specific twisting angle ψ around the axis is depicted in the direction of a line of centriod. In the distribution curve 71 before the maximum value, an approach distance L measured between a pair of dies is multiplied by the specific twisting angle ψ, a relative rotation angle C required between a pair of dies is derived. In the distribution curve 71 after the maximum value, the relative rotation angle C is specified by the integral value of the specific twisting angles ψ around the axis calculated over the approach distance L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elongate material passing through a first and a second mold one after another torsion deformation through relative rotation of the first and second molds caused around the axis of the elongate material. More particularly, the present invention relates to a control data generation method for generating control data used in such a twisting machine.

[0002] In the present specification, a "curve" includes not only a curved line but also a line (for example, a polygonal line) drawn by connecting line segments.

[0003]

2. Description of the Related Art For example, when a pair of dies grip both ends of a straight long metal member (for example, a bar or a square member), relative rotation is caused between the dies around the axis of the long member. However, torsional deformation is caused in the long material. According to this torsion deformation, the long material is twisted at a uniform twist angle between the pair of dies.

[0004]

In recent years, in the field of industrial products such as automobiles, in addition to designs realized by twisting long materials at a uniform twist angle, long products having a gradually changing twist angle are used. Designs realized by twisting materials are emerging. Up to now, no twisting machine capable of causing twisting deformation of a long material according to such a complicated design has been proposed.

The present invention has been made in view of the above situation, and uses a pair of dies that relatively rotate around the axis of a long material, twists the long material at different twist angles along the axis. It is an object of the present invention to provide a method for creating control data for twisting processing capable of performing processing.

[0006]

According to the present invention, there is provided, in accordance with the present invention, a step of obtaining shape data representing a shape of a long product twisted around an axis, based on the shape data. Calculating a relative torsion angle around the axis per unit feed amount specified in the axial direction; and a first and second type of relative rotation around the axis based on the calculated relative torsion angle around the axis. Calculating a twist angle around the axis of the long product between them.

[0007] According to this control data creation method, the twist angle of the long product that fluctuates along the axial direction can be represented by the relative twist angle around the axial center. Between the first and second molds that realize the torsional deformation of the long material, the torsional angle around the axis can be specified based on the relative torsional angle around the axis. While the long material passes through the first and second molds,
If the rotation of the first mold or the second mold is controlled according to the specified twist angle around the axis, twisting deformation can be caused in the long material according to the twist angle defined by the shape data. At this time, the twist angle may gradually increase or gradually decrease. Such shape data may be imported from, for example, a CAD (computer-aided design) system.

In calculating the torsion angle around the axis, the method for creating control data for torsion processing includes a step of specifying a distribution curve indicating a variation in the relative torsion angle around the axis along the axis direction. Detecting the maximum value of the relative torsion angle around the axis above, and the approach distance measured between the first and second types to the relative torsion angle around the axial center specified on the distribution curve leading to the maximum value And a step of multiplying by

When a torsion is applied to the elongated member through the relative rotation of the first and second molds, the elongated member is twisted at a uniform twist angle between the first and second molds. At this time, the relative twist angle around the axis is uniformly distributed between the first and second types along the axis of the long material. For example, if the twist is caused in advance in the first and second molds at a partially uniform relative torsion angle around the axis in advance, even if relative rotation occurs between the first and second molds, work hardening occurs. Due to this, no torsion is caused in a region having a uniform torsion angle around the axial center. Twist occurs first from an area without any twist. When the relative twist angle around the axis in the region to be twisted reaches the above-mentioned uniform value, the long material is twisted evenly over the entire length between the first and second molds thereafter.

According to such a characteristic of the twisting, for example, while the long material successively passes through the first and second molds along the axial direction, the relative rotation angle between the first and second molds is changed. When gradually increased, the torsion angle gradually increases in the long material fed from the second mold. In controlling the relative rotation between the first and second molds in this manner, the relative twist angle around the axis may be multiplied by the approach distance between the first and second molds.

In this case, it is preferable that the local maximum value and the local minimum value adjacent to the local maximum value are averaged in the distribution curve, and the distribution curve reaching the maximum value is redrawn as a simple increase curve. If the distribution curve is redrawn with the simple increase curve in this manner, it becomes possible to derive optimal twisting control data for controlling the first and second dies arranged apart from each other.

On the other hand, in the method for creating control data for twisting, the twist angle around the axis is calculated over the approach distance based on the distribution curve passing through the maximum value when calculating the twist angle around the axis. The method may further include a step of calculating an integral value of.

According to the characteristics of the above-mentioned twisting, the relative rotation angle between the first and second dies, for example, while the long material successively passes through the first and second dies along the axial direction. Is gradually reduced, the torsion angle is gradually reduced in the long material fed from the first mold toward the second mold. In controlling the relative rotation between the first and second types as described above, the integral value of the relative twist angle around the axis may be calculated over the approach distance.

In this case, it is preferable that the local maximum value and the local minimum value adjacent to the local maximum value are averaged in the distribution curve, and the distribution curve passing through the maximum value is redrawn as a simple decreasing curve. If the distribution curve is redrawn with the simple decreasing curve in this manner, it becomes possible to derive optimal twisting control data for controlling the first and second dies arranged apart from each other.

Further, it is desirable that the distribution curve sandwiching the maximum value is redrawn as a straight line showing a uniform twist ratio around the axis center at least over the approach distance. If the distribution curve sandwiching the maximum value is redrawn in a straight line,
As described above, it is possible to derive optimal twisting control data when controlling the first and second dies that are spaced apart from each other.

The above-described method for creating control data for twisting may be configured as a software program executed by a computer. Such a software program may be loaded into a computer through a portable recording medium such as an FD (floppy (registered trademark) disk), a CD (compact disk), and a DVD (digital video disk). It may be taken into a computer through a network such as a WAN (Wide Area Communication Network) or the Internet.

[0017]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows the entire structure of a press-through bending machine. This push-through bending machine 10 is a long material 1
It includes a pair of first and second dies, ie, a fixed mold 12 and a movable mold 13, for guiding the forward movement of the first mold 1, that is, a fixed mold 12 and a movable mold 13, and a feed mechanism 14 for feeding the long material 11 toward the fixed mold 12 and the movable mold 13. In the push-through bending machine 10, as described later, when the movable die 13 moves in a plane orthogonal to the traveling direction of the long material 11, bending deformation (plastic deformation) is caused in the long material 11.

The feed mechanism 14 includes, for example, a pusher, ie, a slider 15 that contacts the rear end of the long material 11, and a screw shaft 17 that converts the rotational force of the feed motor 16 into a propulsive force of the slider 15. When the screw shaft 17 rotates in the forward direction by the action of the feed motor 16, the slider 15 moves forward in accordance with the rotation, and when the screw shaft 17 rotates in the reverse direction, the slider 15 can retreat. The advance of the slider 15 causes the elongate member 11 to advance. The amount of advance of the slider 15, that is, the amount of feed of the long material 11, can be determined according to the amount of rotation of the screw shaft 17, that is, the amount of rotation of the feed motor 16. A so-called servo motor may be used as the feed motor 16.

In such a press-through bending machine 10, a solid long material or a hollow long material 11 can be machined. The hollow long member 11 can be represented by, for example, an extruded member made of aluminum, that is, a shape member or an iron pipe member. Generally, in the long material 11, a common cross-sectional shape is defined over its entire length. However, the cross-sectional shape does not always need to be constant over the entire length of the long material 11.

The feed mechanism 14 and the fixed mold 12 described above are supported by a so-called pendulum member 19. As is apparent from FIG. 2, the cylindrical outer peripheral surface of the pendulum member 19 is supported by the support base 21 through the bearing 20 arranged along the semi-cylindrical surface. According to the operation of the pendulum member 19, the long material 1
1 can rotate together with the fixed mold 12 around the central axis 22 of the fixed mold 12. Such rotation produces a relative rotation between the fixed mold 12 and the movable mold 13 around, for example, the axis of the elongated material 11 as described later. This relative rotation causes the long material 11 to twist and deform around the axis of the long material 11. The rotation of the pendulum member 19 may be realized through the operation of the drive motor 23 composed of, for example, a servomotor.

As shown in FIG. 2, the fixed mold 12 includes
A through-hole 24 is formed that looks like the outer shape of the long material 11. The forward movement of the long material 11 is guided by the through holes 24. The cross-sectional shape of the long material 11 is the through hole 2 shown in FIG.
As apparent from FIG. 4, not only a simple shape such as a circle, an ellipse, a triangle, and other polygons, but also other complicated shapes may be used. The shape of the through hole 24 may be adjusted to the sectional shape of the long material 11.

As is apparent from FIG. 2, the hollow long material 1
When 1 is processed, it is desirable that a core metal, that is, a core 25 be inserted into the hollow space of the long material 11 surrounded by the fixed mold 12. As is well known, in the push-through bending machine 10, the largest bending stress acts on the long material 11 near the exit of the fixed die 12 side through hole 24. At this time, if the long member 11 is hollow, the cross-sectional shape of the long member 11 may be crushed at the edge of the through hole 24. As a result, a large error occurs in the amount of bending deformation of the long material 11 or an unnecessary depression is formed on the outer peripheral surface of the long material 11. If the core 25 comes into contact with the inside of the long member 11, such crushing of the long member 11 can be avoided as much as possible.

As is clear from FIG. 1, the core 25 includes:
A control motor 26 for moving the core 25 back and forth is connected. The core 25 is moved in and out of the long material 11 by the operation of the control motor 26. Moreover, in the present embodiment, a control motor 27 that rotates the core 25 around the central axis 22 of the fixed mold 12 is connected to the core 25. As described above, when the fixed mold 12 rotates around the central axis 22 with the rotation of the pendulum member 19, the control motor 27 can rotate the core 25 around the central axis 22 in accordance with this rotation. As the control motors 26 and 27, for example, a servo motor may be used.

Referring to FIGS. 1 and 3, the movable die 13 is formed with a through-hole 28 that imitates the outer shape of the long material 11, similarly to the fixed die 12. The forward movement of the long material 11 is guided by the through hole 28. It is desirable that the shape of the through hole 28 matches the shape of the fixed mold 12 side through hole 24, for example.

The movable die 13 can move in a moving plane orthogonal to the extension of the central axis 22 of the fixed die 12.
The movement of the movable mold 13 is realized by, for example, a combination of the vertical movement of the vertical movement member 29 and the horizontal movement of the horizontal movement member 30. The vertical moving member 29 is guided by the horizontal moving member 30 so as to be vertically displaceable, that is, vertically displaceable. At the same time, the horizontal moving member 30 is supported by the guide member 31 so as to be displaceable in the horizontal direction. The displacement of the vertical moving member 29 may be realized by the function of the vertical moving motor 32, for example.
May be realized by the operation of the horizontal motion motor 33, for example. For example, the vertical movement motor 32 and the horizontal movement motor 33 may be composed of a servomotor or other drive source capable of controlling the rotation amount of the rotation shaft with a small rotation angle.

Moreover, the position of the movable mold 13 can be changed while changing its position on the above-mentioned moving plane. Such a change in the posture of the movable mold 13 can be achieved by a rotating member 35 having a rotating shaft 34 extending in a vertical direction or a swinging member 37 having a pair of swinging shafts 36 extending in a horizontal direction.
Is realized through the work of When the rotation shaft 34 is received in the support hole 38 formed in the vertically moving member 29, the rotation member 35 can rotate around the vertical axis. On the other hand, when the two swing shafts 36 are received in the support holes 39 formed in the rotating member 35, the swing member 37 can swing around the horizontal axis. The rotation of the rotating member 35 and the swinging of the swinging member 37 may be realized individually by the operation of a drive motor (not shown) constituted by, for example, a servomotor. Here, the swing center of the swing shaft 36 is the center shaft 22.
It is desirable to be orthogonal to the center of rotation of the rotation shaft 34 on the extension of.

FIG. 4 schematically shows the entire structure of a push-through bending system 41 in which the above-described push-through bending machine 10 is incorporated. In the push-through bending system 41, the operation of the push-through bending machine 10 is controlled by an NC (numerical control) controller 42. To realize this control, the NC controller 42 sets a three-dimensional mechanical coordinate system xyz for the push-through bending machine 10 as shown in FIG. 5, for example. The mechanical coordinate system xyz includes, for example, a z-coordinate axis overlapping the central axis 22 of the fixed mold 12 and an x-coordinate axis and a y-coordinate axis respectively defining the horizontal direction and the vertical direction of the fixed mold 12 on one plane facing the exit of the through hole 24. And The posture of the fixed mold 12 specified around the central axis 22, that is, the relative rotation angle about the axis established between the fixed mold 12 and the movable mold 13 is a rotation angle C about the z-axis specified according to the machine coordinate system xyz. Can be identified by

It is desirable that the moving plane HV of the movable mold 13 be held in a posture parallel to the xy plane of the machine coordinate system xyz. According to the setting of the moving plane HV, the movable mold 1
The position of No. 3 can be easily specified by an x-coordinate value or a y-coordinate value specified according to the machine coordinate system xyz. At this time, the z coordinate value of the movable mold 13 may be specified based on a so-called approach distance, that is, a distance between the fixed mold 12 and the movable mold 13. This approach distance is kept constant regardless of the movement of the movable mold 13.

For example, the intersection of the moving plane HV of the movable mold 13 and an extension of the central axis 22 (z coordinate axis of the machine coordinate system xyz) can be set at the reference position of the movable mold 13. When the movable die 13 is positioned at the reference position, the restraining force of the movable die 13 along the moving plane HV is not applied to the long material 11 passing through the two through holes 24 and 28 one after another.
That is, the straight long member 11 goes straight, and no bending deformation is caused on the long member 11 at this time. When the reference position of the movable mold 13 is specified in this manner, the movable mold 1
The posture of No. 3 can be specified by a rotation angle B around the y-axis (V-axis) and a rotation angle A around the x-axis (H-axis) specified according to the machine coordinate system xyz, for example. And movable type 1
When the reference position 3 is established, the axis of the long material 11 is specified by the central axis 22 of the fixed mold 12.

Referring again to FIG. 4, the NC controller 42
Has an engineering workstation (EWS)
An NC processing program calculated by a computer device 43 such as a personal computer (PC) or the like is supplied. The NC processing program includes, for example, a long material 1
Control data such as the position and posture of the movable die 13 and the relative rotation angle around the axis of the fixed die 12 associated with each feed position, that is, each feed amount, are defined. Machine coordinate system x
When the x-coordinate value and the y-coordinate value of the movable mold 13 are designated according to yz, the NC controller 42 defines the rotation amount of the horizontal motor 33 and the vertical motor 32 for establishing such x-coordinate value and y-coordinate value. The drive command value is output to the bending machine 10 by pushing. When the rotation angle B around the y-axis and the rotation angle A around the x-axis of the movable mold 13 are specified according to the machine coordinate system xyz, the NC controller 42 controls the rotation of the rotation member 35 and the swing member 37 that establish these rotation angles. The drive command value of the drive motor to be caused is pushed and output to the bending machine 10. Further, when the rotation angle C around the z-axis of the fixed mold 12 is specified according to the machine coordinate system xyz, the NC controller issues a drive command to the drive motor 23 to cause the rotation of the pendulum member 19 to establish the rotation angle C around the z-axis. The value is pushed to the bending machine 10 and output.

The computer device 43 includes an N for realizing the control data creating method for a push-through bending machine according to the present invention.
C processing program creation software is incorporated. This NC processing program creation software is, for example, a CA that realizes a computer-aided design (CAD) system.
It can function as one module of D software (so-called add-on software). Thus CA
When incorporated in the D software, the NC machining program creation software can use existing functions incorporated in the CAD software in implementing the control data creation method. However, the NC machining program creation software does not necessarily need to be incorporated into the CAD software, and all necessary functions may be provided by the NC machining program creation software alone. NC machining program creation software
For example, the FD (Floppy Disk) 44, CD (Compact Disk) 45, DVD (Digital Video Disk), or other portable recording medium may
3 or may be incorporated in the computer device 43 via a network, whether wireless or wired.

In realizing the control data creating method for the push-through bending machine according to the present invention, the NC machining program creating software is a long-size machine through a network 46 such as a LAN (local communication network), WAN (wide area communication network), or the Internet. Get product shape data.
Using the acquired shape data, the NC machining program creation software creates the NC machining program as described above.

The shape data may be fetched from a product database constructed in the server computer 47, for example. In the product database, for example, CAD data of a product designed on the CAD terminal 48 may be stored.
Such CAD data is, for example, FD
(Floppy disk), CD (compact disk), DVD (digital video disk), and other portable recording media, and may be taken into the product database via the network 49 regardless of whether it is wireless or wired. Good.

Now, as shown in FIG. 6, for example, it is assumed that a long product 51 formed by bending and twisting a profile having a uniform cross section is designed. CAD
The long product 51 designed on the system is stored in the product database as CAD data. Such CAD data includes a long product 5 according to a single global coordinate system XYZ.
At least shape data expressing the shape of the first shape is included.
An expression method such as a wire frame model, a surface model, or a solid model may be used for the shape data. The shape data includes at least the cross-sectional shape of the long product 51 and the long product 5 over the entire length of the long product 51.
What is necessary is just to specify the degree of bending and the degree of twisting. The degree of bending or twisting of the long product 51 can be represented by two curves (for example, ridge lines) passing through the same position in each cross section.

First, the operator starts up the NC machining program creation software on the computer device 43.
The NC machining program creation software fetches the shape data of the long product 51 from the product database based on the input operation of the operator. For example, a keyboard or a mouse may be used for the input operation. Based on the captured shape data, a long product 51 is displayed on the screen of the computer device 43.
Can be reproduced. For this reproduction, for example, an image processing function of CAD software may be used.

When the three-dimensional shape of the long product 51 is confirmed in this way, the NC processing program creation software determines the feed position W of the long material 11 passing through the through hole 24 of the fixed die 12. The feed position W may be defined, for example, based on the last retreat position of the slider 15 established when the long material 11 is set in the push-through bending machine 10, that is, a standby position before processing. When the feed position W is set based on such a reference, the z-coordinate value of the feed position W decreases to the minus side as the slider 15 advances and feeds the long material 11. Such a feed position W is, as described later,
It is determined based on the neutral axis extending in the longitudinal direction of the long product 51.

When the feed position W is determined, the NC machining program creation software determines, for each feed position W, the position and orientation of the movable die 13 and the fixed die 12 with respect to the movable die 13.
And the relative rotation angle around the axis. The position of the movable mold 13 may be defined based on, for example, the x coordinate value and the y coordinate value of the machine coordinate system xyz. The posture of the movable mold 13 may be defined based on, for example, the rotation angle B around the y-axis and the rotation angle A around the x-axis in the machine coordinate system xyz. The relative rotation angle about the axis of the fixed mold 12 may be defined based on, for example, the rotation angle C about the z-axis in the machine coordinate system xyz. Control data can be created based on these x-coordinate values and y-coordinate values, the y-axis rotation angle B, the x-axis rotation angle A, and the z-axis rotation angle C. According to such control data, when the forward speed of the slider 15, that is, the feed speed of the long material 11 is determined, the moving speed of the movable mold 13 in the x-axis direction, the moving speed in the y-axis direction, the rotation speed around the y-axis, the x-axis The rotation speed and the rotation speed around the z-axis of the fixed mold 12 can be determined. As long as the position and posture of the movable mold 13 and the posture of the fixed mold 12 change in accordance with the determined speed, the position and posture of the movable mold 13 and the fixed mold 12 and the movable mold 13 specified by the control data for each feed position W. Can be reliably established.

An NC program header or NC
When the description of the program footer is added, the NC machining program is completed, for example, as shown in FIG. The completed NC machining program is finally sent to the NC controller 42
Supplied to The NC controller 42 operates the push-through bending machine 10 according to the NC machining program.
According to the NC machining program shown in FIG.
1 is a fixed type with a constant feed speed F = 6000 mm / min.
And the movable mold 13. For example, feed position W =-
When 1424.4000 mm is established, the movable mold 13
X from the reference position, ie, the origin position of the moving plane HV,
Coordinate value X = 0.000 mm and y coordinate value Y = 0.44
Move to the coordinate position specified by 6 mm. At this time, the attitude of the movable die 13 is specified by a rotation angle B around the y-axis B = 0.000 degrees and a rotation angle A around the x-axis A = 0.159 degrees. Subsequently, the long material 11 is fed at the feed position W = -1504.072 mm.
Is reached, the movable mold 13 moves to the x-coordinate value X = 0.000.
Move to the coordinate position specified by the mm and y coordinate values Y = 4.409 mm. At this time, the posture of the movable mold 13 is y
Axial rotation angle B = 0.000 degrees and x-axis rotation angle A
= 3.157 degrees. For example, when the long material 11 reaches the feed position W = -1601.907 mm, the movable mold 13 moves to a coordinate position specified by the x coordinate value X = 0.090 mm and the y coordinate value Y = 8.515 mm. At this time, the attitude of the movable mold 13 is such that the rotation angle B around the y-axis B = −0.065 degrees and the rotation angle A around the x-axis A =
The posture changes to 6.092 degrees. At the same time, the fixed mold 12 rotates around the central axis 22 and changes to a posture defined by a rotation angle C around the z-axis = 0.7091 degrees. Thus, each time the movable die 13 passes each feed position W, x
While moving to the position defined by the coordinate value X and the y coordinate value Y, the posture changes to the posture defined by the y-axis rotation angle B and the x-axis rotation angle A. At the same time, relative rotation defined by the rotation angle C about the z-axis is established between the fixed mold 12 and the movable mold 13. Between the adjacent feed positions W, the x-coordinate value X and the y-coordinate value Y, the y-axis rotation angle B, the x-axis rotation angle A, and the z-axis rotation angle C may change at a constant speed, for example.

In determining the feed position W, the NC machining program acquires the center of gravity of the long product 51. The center of gravity line specifies the position of the center of gravity specified in each cross section over the entire length of the long product 51. In specifying this center of gravity line, the NC processing program creation software uses two-dimensional data representing the cross-sectional shape 52 of the long product 51 and the cross-sectional shape 52 as shown in FIGS.
And three-dimensional data representing the ridge line corresponding to each vertex. However, in associating each vertex of the cross-sectional shape 52 with each ridge line, the chamfer formed at each vertex is ignored. That is, the ridge line is drawn by the vertex before the cornering used in the drawing process of the cross-sectional shape 52.

More specifically, the NC machining program creation software first obtains the correspondence between each vertex of the cross-sectional shape 52 specified by the two-dimensional data and the ridge line specified by the three-dimensional data. For this acquisition, for example, a GUI (graphic user interface) may be used.
That is, the operator designates the first and second guide lines 53a and 53b based on the three-dimensional image of the ridge line drawn on the screen of the computer device 43 as shown in FIG. As shown in FIG. 5, based on the cross-sectional shape 52 drawn on the screen, for example, first and second
The guide points 54a and 54b are designated. Here, the first guide line 53a and the first guide point 54 are specified in the specified order.
a are associated with each other, and the second guide line 53b and the second
The guide points 54b are associated with each other. For such designation, for example, a mouse operation may be used.

When the two-dimensional data and the three-dimensional data are associated with each other, the NC machining program creation software obtains the positional relationship between the two guide points 54a and 54b and the center of gravity 55 along the cross section. For example, G
A UI may be used. That is, the operator may superimpose the xy coordinate system on the cross-sectional shape 52 of the long product 51 drawn on the screen of the computer device 43, as shown in FIG. When the xy coordinate system is set in this way, the NC machining program creation software sets the x and y of the first and second guide points 54a and 54b in accordance with the xy coordinate system.
The coordinate value and the y coordinate value and the x coordinate value and the y coordinate value of the center of gravity 55 are calculated. However, here, two guide points 5
It is sufficient that the relative positional relationship of the center of gravity 55 with respect to 4a and 54b is derived. If the coordinate origin of the xy coordinate system is superimposed on the center of gravity 55 as shown in FIG. 8, it is not necessary to calculate the x coordinate value and the y coordinate value of the center of gravity 55.

Subsequently, as shown in FIG. 10, the NC machining program creation software executes two ridge lines defined by the three-dimensional data, that is, first and second guide lines 53.
A plurality of cutting planes 57a to 57g are defined for a and 53b. In setting the cutting planes 57a to 57g, the first and second guide lines 53a and 53b may be equally divided into the same number of partial lines. Each cutting plane 57a
57g are orthogonal to the tangents of the first and second guide lines 53a and 53b at the division points 58a to 58g of the partial line. In each of the cutting planes 57a to 57g, the first guide point 5 is located at a position where the first guide line 53a intersects with the cutting planes 57a to 57g.
4a can be specified, and the second guide point 54b can be specified at a position where the second guide line 53b intersects the cutting planes 57a to 57g.

When the positions of the first and second guide points 54a and 54b are specified on each of the cutting planes 57a to 57g in this manner, the NC machining program creation software makes the two guide points 54a and 54b and the center of gravity as described above. The center of gravity 55 on the cutting planes 57a to 57g
Identify the location of When the calculated centers of gravity 55 are connected in order, for example, as shown in FIG.
The barycentric line 59 can be drawn. If the continuity of curvature is considered when connecting the centers of gravity 55, a smooth and accurate center of gravity line 59 can be obtained. In addition, to improve the accuracy of the barycentric line 59 thus obtained,
It is desirable that the interval between the centers of gravity 55, that is, the interval between the cutting planes 57a to 57g be reduced. The center of gravity line 59 expresses the degree of bending of the long product 51.

The barycentric line 59 can be represented by a parametric curve such as a Bezier curve, a B-spline curve, or a NURBS (non-uniform rational B-spline) curve. In such an expression method, for example, as shown in FIG.
2, 63. These control points 62 and 63 always include a knot 62 that gives a coordinate value on a represented curve 61. The arrangement of the knots 62 is determined based on the difference between the straight line 64 connecting the adjacent knots 62 and the represented curve 61, that is, the tolerance TOL. As a result of keeping the tolerance TOL constant, the interval between the knots 62 is reduced in the curve 61 having a large curvature, and conversely, the interval between the knots 62 is increased in the curve 61 having a small curvature. In addition, if the tolerance TOL increases, the interval between the knots 62 increases, and if the tolerance TOL decreases, the interval between the knots 62 decreases.
At the center of gravity line 59, the length of the curve 61 between adjacent knots 62 is measured.

When the interval between the knots 62 is thus obtained along the center of gravity line 59, the NC machining program creation software, for example, as shown in FIG.
Fixed type 1 in the global coordinate system XYZ that specifies the three-dimensional shape of
A local coordinate system, ie, a machine coordinate system x specified on the basis of
yz is specified. Such a machine coordinate system xyz may be set based on the cross sections 65a to 65g defined for each knot 62 specified on the barycentric line 59 as described above.

In specifying each of the cross sections 65a to 65g, the NC machining program creation software, for example, as shown in FIG.
, A tangent vector 66 is calculated. In each knot 62, a cutting plane 67 to which the tangent vector 66 is orthogonal can be specified. Depending on the cross-sectional shape of the long product 51 drawn on the cutting plane 67, each cross section 65a to 65
g can be specified. In this manner, each of the cross sections 65a to 65a according to the barycentric line 59 expressed by the parametric curve.
When 5 g is specified, as the curvature of the long product 51 increases, the number of sections 65 a to 65 g increases, and the movement of the movable mold 13 can be finely controlled. In addition, if the size of the tolerance TOL is intentionally changed, the cross-section 6 may be changed according to the dimensional accuracy required for the long product 51.
The number of sheets of 5a to 65g can be changed intentionally.

In drawing out the cross-sectional shape of the long product 51 on each cutting plane 67, the NC machining program creation software uses the through-hole 24 of the fixed die 12 and the machine coordinate system xyz.
Get the positional relationship with. For this acquisition, for example, a GUI may be used. That is, for example, the operator
As shown in (2), the machine coordinate system xyz may be aligned with the cross-sectional shape of the long product 51 drawn on the screen of the computer device 43. At this time, the directions of the x-coordinate axis and the y-coordinate axis of the machine coordinate system xyz are set according to the shape of the through-hole 24 formed in the fixed die 12, that is, the direction around the central axis 22. The direction of the z coordinate axis coincides with the center axis 22 of the fixed mold 12. Here, the central axis 2 of the fixed mold 12
2 corresponds to the center of gravity G specified by the cross-sectional shape of the long product 51, for example. As a result, as described above, the long product 51 is represented by the barycentric line 59 representing the degree of bending of the long product 51.
Can be specified.

The machine coordinate system x for each of the cross sections 65a to 65g
When yz is set, the NC machining program creation software specifies the position and posture of the movable mold 13 based on the center of gravity line 59, for example, as shown in FIG. In this specification, the NC machining program creation software firstly sets the fixed mold 12 and the movable mold 13 on the machine coordinate system xyz.
Is specified. The approach distance L is measured along the center axis 22 of the fixed mold 12 between the exit of the fixed mold 12 side through-hole 24 and the movable mold 13 positioned at the reference position. Such an approach distance L may be previously taken into the NC machining program creation software through, for example, an input operation of the operator.

The moving plane HV of the movable mold 13 is defined on the machine coordinate system xyz based on the specified approach distance L. In defining the movement plane HV, the NC machining program creation software may define the z coordinate value on the machine coordinate system xyz based on the approach distance L. As a result, the xy plane of the machine coordinate system xyz is translated along the z coordinate axis by the approach distance L. When the movement plane HV is defined in this way, the NC machining program creation software calculates the x coordinate value and the y coordinate value at the intersection 68 between the movement plane HV and the center of gravity line 59. The geometric position of the movable mold 13 can be specified by the calculated x-coordinate value and y-coordinate value. Movable mold 1 specified in this way
The three-dimensional shape of the long product 51 specified by the shape data is simply reflected in the third geometric position.

As described above, in obtaining the x coordinate value and the y coordinate value of the movable mold 13 in accordance with the machine coordinate system xyz,
The three-dimensional image of the long product 51 may be projected on the yz plane or the xz plane of the machine coordinate system xyz. For example, as shown in FIG. 17, a three-dimensional image of the long product 51 is represented by a machine coordinate system xyz.
Is projected on the yz plane, the y coordinate value of the movable mold 13 can be specified based on the intersection of the projected three-dimensional image and the moving plane HV. At this time, if the tangential direction 69 of the long product 51 is specified on the moving plane HV, the rotation angle A around the x-axis of the movable mold 13 can be derived. FIG.
As shown in the figure, when the three-dimensional image of the long product 51 is projected on the xz plane of the machine coordinate system xyz, similarly, based on the intersection of the projected three-dimensional image and the moving plane HV, the movable mold 13
Can be specified. At the same time, if the tangential direction 70 of the long product 51 is specified on the moving plane HV, the rotation angle B around the y-axis of the movable mold 13 can be derived.

At the same time as specifying the position and posture of the movable mold 13 in this manner, the NC machining program creation software
Attitude around the central axis 22 of the fixed mold 12, based on the machine coordinate system xyz set for each of the cross sections 65a to 65g,
Fixed mold 12 that rotates relative to the movable mold 13 about the axis.
Specify the relative rotation angle around the axis. In this specification, the NC processing program creation software firstly uses the adjacent machine coordinate system xyz to determine the torsion ratio around the axis per unit feed amount specified along the axial direction of the long product 51, that is, along the center line 59. Calculate the angle.

In calculating the relative twist angle around the axis,
The NC machining program creation software is, for example, as shown in FIG.
As shown in the figure, between adjacent machine coordinate systems xyz
Superimpose the xy coordinate planes on each other. This superposition
For example, using a matrix operation or the like,
If the direction of the z coordinate axis is aligned between the machine coordinate systems xyz
Good. When overlaying such coordinate planes,
xy coordinate plane and x ₁y₁In the coordinate plane, the global coordinate system
The rotation angle around the z coordinate axis is maintained according to XYZ. I
Thus, the superposed xy coordinate plane and x₁y
₁Based on the coordinate plane, a pair of cross sections 65a and 65b
Between the torsion angles θ around the axis can be derived.

When the torsion angle θ around the axis is calculated between the adjacent cross sections 65a to 65g in this manner, the NC machining program creation software executes the processing of the cross sections 65a to 65g as described above.
Using the length of the center-of-gravity line 59 measured between 65 g, that is, the length of the curve 61 measured between the knots 62, the relative twist angle 軸 around the axial center is calculated. That is, the twist angle θ around the axis is divided by the length of the center line 59. The torsion angle ψ around the axial center calculated in this way is plotted one after another with respect to the accumulated length of the center-of-gravity line 59 as shown in FIG. 20, for example. As a result, the distribution curve 7 showing the variation of the relative twist angle 軸 around the axial center along the axial direction of the long product 51.
1 is derived. However, in the distribution curve 71, the fixed mold 12 is located at the axial position specified by the length of the center of gravity line 59.
Is plotted, the relative torsion angle 軸 around the axis specified at the position of the movable mold 13 when is positioned.

Subsequently, the NC machining program creation software sets the maximum value 72 of the twist ratio 回 り around the axis on the distribution curve 71.
Is detected. The maximum value 72 is obtained by calculating the relative twist angle around the axis ψ =
It is detected in one torsion section 73 that starts at 0 and ends with the relative twist angle 軸 = 0 around the axis. When the maximum value 72 is detected, NC
The machining program creation software redraws the distribution curve 71a that reaches the maximum value 72 as a simple increase curve, and also redraws the distribution curve 71b that has passed the maximum value 72 as a simple decrease curve. According to the simple increase curve, the relative twist angle around the axis ψ = 0
From the maximum value 72 to the maximum value 72, the relative twist angle 軸 does not decrease, and according to the simple decrease curve, the relative twist angle 軸 increases from the maximum value 72 to the specific twist angle 軸 = 0. I will not do it. In the distribution curve 71a reaching the maximum value 72 and the distribution curve 71b passing through the maximum value 72, for example, as shown in FIG. 21, the maximum value 75 and the minimum value 76 adjacent to the maximum value 75 are averaged. . As is clear from FIG. 21, the straight line 77 drawn by the averaging has a region 78 defined between the distribution curve 71 including the local minimum value 76 and the distribution curve 71 including the local maximum value 75 and the straight line 77. A region 79 having the same area as is defined.

When the distribution curve 71 is represented by a simple increase curve and a simple decrease curve, the NC machining program creation software draws a machining area 81 based on the approach distance L as shown in FIG. 22, for example. The machining area 81 includes an upper side 82 that specifies the approach distance L in the axial direction, that is, the length direction of the center of gravity line 59, and an upper side 82
Are enclosed by a movable-type oblique side 83 and a fixed-type oblique side 84 that specify the allowable change rate of the torsional angle 軸 around the axis by the degree of inclination. The allowable change rate is determined based on, for example, the maximum rotation speed around the central axis 22 of the fixed mold 12.

The NC machining program creation software is
In the distribution curve 71 a reaching the maximum value 72, the processing area 81 is moved along the distribution curve 71 based on one end of the upper side 82 that specifies the position of the movable die 13. When the processing area 81 intersects the distribution curve 71 at other than one end of the upper side 82 during the movement, NC
The machining program creation software redraws the distribution curve 71 along the outer frame of the machining area 81 in the intersecting area. Conversely, in the distribution curve 71b passing through the maximum value 72, the machining area 8 is determined based on the other end of the upper side 82 that specifies the position of the fixed mold 12.
1 is moved along the distribution curve 71. If the processing area 81 intersects the distribution curve 71 other than the other end of the upper side 82 during the movement, the distribution curve 71 is similarly drawn along the outer frame of the processing area 81 in the intersecting area. At the same time, the distribution curve 71 sandwiching the above-described maximum value 72 is redrawn on a straight line 85 indicating a uniform torsion angle 軸 around the axis center at least over the approach distance L based on the machining area 81, as is apparent from FIG. It is. According to such a straight line 85, the distribution curves 71 sandwiching the maximum value 72 are averaged.

When the distribution curve 71 is completely redrawn based on the machining area 81 in this way, the NC machining program creation software executes the respective sections 65a to 65c along the length of the center line 59.
The rotation angle around the central axis 22 of the fixed mold 12 is calculated every 65 g. That is, the NC processing program creation software sets the movable type to the torsion angle ψ around the axial center specified for each of the cross sections 65a to 65g on the distribution curve 71 reaching the entrance 86 of the straight line 85, as is apparent from FIG. Multiply the approach distance L measured between 13 and the fixed mold 12. By this multiplication, the rotation angle C about the z-axis of the fixed mold 12 is derived. On the other hand, the NC machining program creation software calculates the integral value of the torsion angle 軸 around the axis center over the approach distance L for each of the cross sections 65a to 65g based on the distribution curve 71 passing through the entrance 86 of the straight line 85. The z-axis rotation angle C of the fixed mold 12 can be specified by the integrated value.

Here, the principle of the above-mentioned twisting will be briefly described. Now, when the fixed die 12 rotates around the central axis 22 at the rotation angle θ1, for example, as shown in FIG. 24, the long material 11 is twisted between the fixed die 12 and the movable die 13. If the cross-sectional shape is uniform,
The long material 11 is twisted evenly between the fixed mold 12 and the movable mold 13. Therefore, as shown in FIG. 25, the specific twist angle ψ1 is uniformly distributed over the approach distance L.
The specific twist angle ψ means a twist angle per unit length along the axial direction of the long material 11.

When the long material 11 is fed in the axial direction at a minute distance D1, the above-mentioned specific twist angle ψ1 is maintained in the long material 11 that has passed through the movable die 13. At this time, if the fixed mold 12 establishes the posture specified by the rotation angle θ2 larger than the rotation angle θ1, the elongated material 11 is twisted evenly between the fixed mold 12 and the movable mold 13 as shown in FIG. As shown in FIG. 26, the specific twist angle 分布 2 is uniformly distributed between the fixed mold 12 and the movable mold 13. When the long material 11 passes through the movable mold 13 again at the minute distance D2 while maintaining the specific torsion angle ψ2, as shown in FIG. 27, following the specific torsion angle ψ1 realized over the minute distance D1, A specific twist angle ψ2 can be realized over the distance D2.

When the feeding of the minute distance and the rotation of the fixed mold 12 are continuously repeated in this manner, the long material 11 is torsionally deformed at the specific torsion angle す る gradually increasing. For example, if the rotation angle of the fixed mold 12 is smoothly changed while continuously feeding the long material 11 in the axial direction, as described above, the long product 51 twisted with the gradually increasing twist angle is obtained. Can be done. At this time, the rotation angle of the fixed mold 12 is determined by the specific twist angle で specified by the position of the movable mold 13 and the approach distance L.
And multiplication by

Subsequently, as described above, the uniform specific twist angle ψ1
It is assumed that the long material 11 is sent at a small distance D1 while releasing the restraining force applied to the fixed mold 12 after the long material 11 is twisted by allowing the fixed mold 12 to rotate around the central axis 22. I do. Then, as shown in FIG. 28, the minute distance D
Twist does not occur in the long material 11 passing through the fixed mold 12 while being sent in 1. As a result of the twisted elongated member 11 passing through the movable die 13, a rotation angle θ3 about the axis is generated in the elongated member 11 in a direction opposite to the rotation angle θ1 of the fixed die 12. Fixed type 12
Is reduced to (θ1−θ3). As shown in FIG. 29, the long material 11 passing through the fixed mold 12 while being sent at the minute distance D1 maintains the specific twist angle ψ = 0.

Thereafter, when the restraining force applied to the fixed mold 12 is restored and the fixed mold 12 is forcibly rotated about the central axis 22, for example, as shown in FIG. , Due to work hardening, the specific twist angle ψ
No torsional deformation is induced until a value of 1 is reached. At this time, in the long material 11, as described above, twisting occurs uniformly over the minute distance D1. As a result, a uniform specific twist angle 均一 4 is distributed at the minute distance D1. As can be seen from FIG. 30, the rotation angle of the fixed mold 12 can be specified by the integral value of the specific twist angle さ れ る calculated over the approach distance L between the fixed mold 12 and the movable mold 13.

Subsequently, the long material 11 is sent out again in the axial direction at the minute distance D2, and the specific torsion angle ψ = 0 is maintained in the long material 11 that has passed through the fixed mold 12, as described above. afterwards,
When the fixed mold 12 is forcibly rotated around the central axis 22,
For example, as shown in FIG. 31, following the specific twist angle ψ4 realized over the minute distance D1, a specific twist angle ψ5 can be realized over the minute distance D2. However,
The specific twist angle ψ5 must be smaller than the preceding specific twist angle ψ4.

When the feeding of the minute distance and the rotation of the fixed mold 12 are continuously repeated in this manner, the long material 11 is torsionally deformed at the specific torsion angle す る gradually reduced. For example, if the rotation angle of the fixed mold 12 is smoothly changed while continuously feeding the long material 11 in the axial direction, as described above, the long product 51 twisted with the gradually decreasing twist angle is obtained. Can be done.

As described above, when the posture of the fixed mold 12 and the position and posture of the movable mold 13 are specified for each of the cross sections 65a to 65g, for example, as shown in FIG. Then, the neutral axis 91 is drawn.
In drawing such a neutral axis 91, the NC machining program creation software calculates the amount of deviation η from the center of gravity line 59, that is, the center of gravity 55 to the neutral axis 91 along each of the cross sections 65a and 65b. The details of the calculation process of the deviation amount η will be described later. The NC machining program creation software draws the neutral axis 91 based on the calculated deviation amount η and the center of gravity line 59.

In drawing the neutral axis 91 based on the center line 59, the NC machining program creation software
The direction vector of the barycentric line 59 is specified on each of the cross sections 65a and 65b. These directional vectors are cross sections 65a, 65b
Along with the deviation amount η. As a result, a start point vector and an end point vector are specified between two adjacent cross sections 65a and 65b. The center line 59 between the start point vector and the end point vector specified in this way.
A parametric curve of the same order as is drawn. The curvature of the parametric curve can be changed from the start point vector to the end point vector at an equal change rate. The neutral axis 91 is represented by such a parametric curve. When such processing is realized between all the cross sections 65a to 65g, the neutral shaft 91 can be drawn over the entire length of the long material 11.

The feed amount of the long material 11 between the adjacent cross sections 65 a and 65 b can be expressed by the length S 1 of the neutral shaft 91. The length S1 of the neutral shaft 91
, The feed position W of the long material 11 is determined. In other words, each cross section 6 specified on the basis of the length of the barycentric line 59
The positions of 5a to 65g, that is, the positions of the knots 62 specified along the center line 59 are corrected based on the length S1 of the neutral shaft 91. Here, after the length S1 of the neutral shaft 91 is substituted for the length S2 of the center-of-gravity line 59, each section 65a-
What is necessary is just to specify the position of 65g.

In general, in the push-through bending machine 10, as shown in FIG. 33, for example, when the long material 11 sent out from the fixed die 12 is bent by the movable die 13,
An axial compression force Pc is applied to the long material 11 by the reaction force of the feeding. Such an axial compression force Pc causes a change in the length of the long material 11. Such a change in length changes according to the curvature 1 / R of the bending, that is, the radius of curvature R. On the other hand, no distortion occurs in the axial direction of the neutral shaft 91 regardless of the degree of bending of the long material 11, that is, the magnitude of the curvature 1 / R. Therefore, the length S1 of the neutral shaft 91 is maintained constant before and after processing. The x- and y-coordinate values of the movable mold 13, the rotation angle B around the y-axis B, the rotation angle A around the x-axis A, and the rotation angle around the z-axis of the fixed mold 12 are provided at the respective feed positions W specified with reference to the neutral axis 91. When C is associated, a long product 51 with high accuracy can be obtained.

Further, as described above, the geometric position of the movable die 13 is determined in accordance with the mechanical coordinate system xyz, that is, the local coordinate system specified based on the fixed die 12 of the push-through bending machine 10. The local coordinate system is redefined each time the feed position defined in the longitudinal direction of the long product 51 changes. Therefore, after the bending deformation of the long product 51 formed between the fixed mold 12 and the movable mold 13 is necessarily incorporated, the x-coordinate value and the y-coordinate value of the movable mold 13 are specified.

Here, a method of calculating the deviation amount η will be described in detail.
This deviation amount η is, as shown below,
It can be derived based on the curvature 1 / R of the long product 51 specified every ~ 65g. Now, for example, FIG.
As shown in (1), when the long material 11 is bent by the movable die 13, a load F acts on the movable die 13 in the radius of curvature direction by the reaction force of the bending deformation. At this time, fixed type 1
When the axial compressive force Pc is specified in the axial direction in the elongated material 11 at the outlet of the two-side through-hole 24,

[0072]

(Equation 1)

Is obtained. Here, the axial compression force Pc
Is equal to the sum of the nominal stress distributions σ (h) of the long material 11 specified at the exit of the fixed mold 12 side through hole 24. Therefore, for example, the curvature 1 / R at the exit of the fixed mold 12 side through hole 24
Is specified, as is apparent from FIG.

[0074]

(Equation 2)

Is obtained. Here, the variable h indicates the distance from the neutral axis 91 measured in the radius of curvature direction, and the coefficient A
Indicates the cross-sectional area of the long product 51, that is, the long material 11.
At this time, the bending moment M is

[0076]

(Equation 3)

## EQU1 ## From the expression (1),
When Expressions 2 and 3 are substituted into

[0078]

(Equation 4)

Is obtained. When this equation [Equation 4] is rearranged,

[0080]

(Equation 5)

Is derived.

In specifying the bending moment M, the NC processing program creation software uses the nominal stress distribution σ (h) and the nominal strain specified along the cross section of the long product 51, that is, the long material 11 being processed. Distribution e
(H) is used. As is apparent from FIG. 34, the nominal strain distribution e (h) changes linearly along the radius of curvature on the cross section of the long product 51, that is, the long material 11. Therefore, the nominal strain distribution e (h) can be geometrically derived based on the position of the center of gravity 55 and the position of the neutral axis 91 specified on the cross section. That is, the center of gravity line 59 is drawn with the radius of curvature R, and the center of gravity 5 is drawn along the radius of curvature on the cross section.
When the deviation amount η is specified from 5 to the neutral axis 91, the nominal strain distribution e (h) becomes

[0083]

(Equation 6)

Can be expressed by

On the other hand, according to the nominal strain distribution e (h) thus specified, the nominal stress distribution σ (h) is

[0086]

(Equation 7)

Can be expressed by In the equation [Equation 7], coefficients C3, C2, C1, and C0 are, for example, as shown in FIG.
Is determined based on a stress-strain curve (SS curve) 93 drawn by a tensile test. That is, according to the polynomial of Expression 7, an approximate curve 94 for the stress-strain curve 93 is derived. The polynomial shown in Equation 7 can be easily specified by, for example, three points such as a maximum strength point 95, a yield point 96, and an intermediate point 97 of the stress-strain curve 93 obtained by the tensile test. .

The NC machining program creation software is
Numerical integration is performed according to equation [5]. When performing this numerical integration, the NC machining program creation software calculates the relationship between the curvature 1 / R and the deviation amount η expressed by the equations [6] and [7] in the above equation [5]. substitute. In this way, when the numerical integration and the convergence calculation are performed after the equations [Equation 6] and [Equation 7] are substituted into the equation [Equation 5], the deviation from the center of gravity 55 to the neutral axis 91 on the specified cross section The quantity η can be calculated.

In addition, when specifying the neutral axis 91, the NC machining program creation software may derive the deviation amount η based on the actually measured data as shown in FIG. 36, for example. According to the measured data,

[0090]

(Equation 8)

The deviation amount η can be calculated according to the following equation. Here, the coefficient α represents the ratio of the amount of deviation η to the height H (= h2−h1) of the long material 11 measured in the radius of curvature direction at each cross section, that is, the movement rate. Height H of long material 11
Is multiplied by the movement rate α, the deviation amount η of the neutral shaft 91 is calculated. In specifying the movement rate α, the proportional coefficient K1 calculated based on the actually measured data may be used.

In obtaining the proportional coefficient K1, it is sufficient that the long material 11 specified by various cross-sectional shapes, materials, and sizes is actually processed by the push-through bending machine 10. At this time, the inclination angle φ of the movable mold 13 being processed and the length of the elongated material 11 after deformation are measured. When the movement rate α of the neutral shaft 91 is plotted against the actually measured inclination angle φ of the movable mold 13, for example, actual measurement data shown in FIG. 36 can be obtained. Here, two types of aluminum materials (JIS6063-T1 and JIS6063-T5)
The inclination angle φ was actually measured. In the actual measurement, the cross-sectional shape and size of each aluminum material were changed. Moreover, four approach distances L = 50 mm, 60 mm, 70 mm, 90 m between the fixed mold 12 and the movable mold 13
m was set. According to the actual measurement data, the long material 11
It is evident that the same coefficient K1 can be used in calculating the deviation amount η regardless of the differences in the cross-sectional shape and material properties.

Further, the NC machining program creation software corrects the above-described geometric position in consideration of various factors, and derives the actual machining position of the movable die 13 that produces a long product 51 with high accuracy as designed. . To derive such actual machining positions, the NC machining program creation software specifies the elastic bending restoring force of the long material 11, that is, the amount of elastic-plastic bending deformation caused by springback, as shown in FIG. 37, for example.

As is clear from FIG. 37, in specifying such an elastic-plastic bending deformation amount, the NC processing program creation software firstly sets the product curvature 1 / Rb of the processed long product 51 specified by the shape data. To get.
Here, Rb indicates a radius of curvature. This product curvature 1 / Rb
May be calculated based on the geometric position of the movable mold 13 specified on the machine coordinate system xyz as described above. That is, the coordinate system shown in FIG. 37 is defined along one plane including the coordinate origin of the machine coordinate system xyz and the geometric position of the movable die 13. Here, the product curvature 1 / Rb is represented by an average curvature measured between the exit of the fixed mold 12 side through hole 24 and the movable mold 13.

Subsequently, the NC machining program creation software calculates the bending moment applied to the long material 11 based on the product curvature 1 / Rb. The bending moment
A bending moment distribution specified between the exit of the fixed mold 12 side through hole 24 and the movable mold 13 may be used. Here, the average bending moment from the outlet of the fixed mold 12 side through hole 24 to the movable mold 13 is used as such a bending moment. For example, as shown in FIG. 37, the average bending moment has
値 of the maximum bending moment M calculated at the exit of may be used. The maximum bending moment M can be derived based on the above equation [Equation 3]. At this time, the deviation amount η calculated as described above, the equation [Equation 6] and the equation [Equation 7] may be referred to.

On the basis of the calculated maximum bending moment M, the NC processing program creation software calculates the amount of elasto-plastic bending deformation. The elasto-plastic bending deformation amount can be calculated, for example, according to the following equation.

[0097]

(Equation 9)

According to this formula [Equation 9], the amount of elasto-plastic bending deformation is equal to the amount of in-process bending required to realize the product curvature 1 / Rb of the long product 51 after processing specified by the shape data. Is represented by the actual curvature 1 / Rc, that is, the actual curvature radius Rc. Here, the coefficient E indicates the Young's modulus (longitudinal elasticity coefficient) of the long material 11, and the coefficient I indicates the second moment of area of the long material 11.

It is sufficient that the Young's modulus E and the second moment of area I are previously taken into the NC machining program creation software based on the input operation of the operator. At this time, the second moment of area I is, as described above,
May be calculated based on the machine coordinate system xyz superimposed on the cross-sectional shape of. When the cross-sectional secondary moment Ix around the x-axis, the cross-sectional secondary moment Iy around the y-axis, and the cross-sectional synergistic moment Jxy are calculated according to the designated machine coordinate system xyz, as is clear from FIG. section two in binormal vector b around which defines the bending direction moment I _b can be calculated.

[0100]

(Equation 10)

Here, θ _bx indicates an angle specified counterclockwise between the binormal vector b and the x coordinate axis of the machine coordinate system xyz. Here, the second moment of area Ix, I
y and the area synergistic moment Jxy are

[0102]

[Equation 11]

Can be calculated by According to the calculated second moment of area _Ib , an appropriate second moment of area I can be specified according to the bending direction for each cross section of the long material 11.

When the actual curvature 1 / Rc is specified, the NC machining program creation software specifies the actual processing position 102 of the movable die 13 based on the center of gravity line 101 redrawn with the actual curvature 1 / Rc. The actual processing position 102 may be represented by an x coordinate value or a y coordinate value according to the machine coordinate system xyz, or may be represented by a difference value from the geometric position 103 based on the barycentric line 59.

Generally, the long material 11 such as an aluminum material undergoes elastic deformation to plastic deformation. Even if the bending deformation is applied from the movable mold 13, the elongated material 11 is released from the movable mold 13, and at the same time, a shape error occurs in the processed long product 51 in accordance with the elastic restoring force, so-called springback. If the actual processing position of the movable mold 13 is specified according to the amount of elastic-plastic bending deformation derived as described above, the shape error of the long product 51 due to such elastic restoring force, so-called springback, is sufficiently eliminated. Can be In particular, since such an elasto-plastic bending deformation amount is geometrically calculated based on the bending moment M, it is possible to save as much time and effort as collecting actual measurement data.

In addition to the above elasto-plastic bending deformation,
For example, the NC machining program creation software is shown in FIG.
As shown in (2), the angle β around the outlet of the long material 11 at the outlet of the fixed mold 12 side through hole 24 may be specified. Such a bending angle β around the outlet is caused by a shearing deformation or a cross-sectional deformation such as an elastic bending deformation or a plastic bending deformation generated at the outlet of the through hole 24, that is, the depression 104. When the exit turning angle amount β is specified, the NC machining program creation software executes the through hole 2 according to the machine coordinate system xyz.
The center of gravity line 59 is rotated around the exit of No. 4. Center of gravity line 59
May be rotated along the one plane including the coordinate origin of the machine coordinate system xyz and the geometrical position of the movable mold 13 with the angle of the turning angle β around the outlet. NC machining program creation software
The actual processing position 105 of the movable mold 13 is specified based on the intersection between the rotated center of gravity line 59 and the moving plane HV. The actual processing position 105 may be represented by an x coordinate value or a y coordinate value according to the machine coordinate system xyz, or may be represented by a difference value from a geometric position based on the barycentric line 59.

In particular, in the case of the hollow long material 11, the fixed mold 12
When bending deformation is caused between the movable mold 13 and the movable mold 13, a large shearing force acts on the long material 11 at the outlet of the fixed mold 12 side through hole 24. Such a shearing force causes a shearing deformation such as an elastic bending deformation or a plastic bending deformation at the outlet of the fixed mold 12 side through hole 24. Moreover, at the exit of the fixed mold 12 side through-hole 24, the elongated material 11 has a cross-sectional deformation, that is, a depression 10.
4 occurs. According to the recess 104, a bending deformation is caused at the exit of the fixed mold 12 side through hole 24. As a result of the bending deformation caused by the shearing deformation and the cross-sectional deformation, a sufficient bending deformation cannot be generated between the fixed mold 12 and the movable mold 13 according to the geometrical positional relationship based on the shape data. Long material 11
Is released from the movable mold 13 and, at the same time, the processed long product 51 has a shape error in accordance with the bending deformation. If the actual processing position 105 of the movable die 13 is specified according to the exit turning angle amount β derived as described above, the shape error of the long product 51 caused by such an exit turning angle is sufficiently eliminated. Can be done.

Here, the exit turning angle β may be specified based on actual measurement data as shown in FIG. 39, for example. According to the measured data,

[0109]

(Equation 12)

The angle angle β [出口] around the exit can be calculated according to the following formula. Here, the coefficient K2 indicates a proportional coefficient calculated based on the actually measured data.

In obtaining such actual measurement data, the long material 11 specified by various cross-sectional shapes, materials, and sizes may be actually processed by the push-through bending machine 10. At this time, the shape of the long material 11 is actually measured between the fixed mold 12 and the movable mold 13. The curvature of the bending deformation is clarified by such actual measurement. For example, as is apparent from FIG. 38, at least three measurement points 106 may be selected to derive the curvature radius Rd of the bending deformation.

When the curve 107 expressing the bending deformation of the long material 11 is specified between the fixed mold 12 and the movable mold 13 in this manner, a tangent line 108 to the curve 107 is drawn at the exit of the through hole 24 on the fixed mold 12 side. . The exit turning angle β can be specified by the angle between the tangent 108 and the z-coordinate axis of the machine coordinate system xyz. When the actually measured exit turning angle β is plotted against the coefficient M / EI, the actually measured data shown in FIG. 39 can be obtained. Here, three types of aluminum materials (JIS
6063-O, JIS6063-T1 and JIS60
63-T5), the exit turning angle β was actually measured. In the actual measurement, three approach distances L = 60 mm, 90 mm, 1
33 mm was set. According to the actual measurement data, it is clear that the same coefficient K2 can be used in calculating the exit turning angle amount β regardless of the cross-sectional shape and the material properties of the long material 11.

Similarly, as shown in FIG. 40, for example, the NC machining program creation software calculates the cross-sectional deformation d1 due to the cross-sectional deformation of the long material 11 at the outlet of the fixed mold 12 side through hole 24, ie, the recess 104. It may be specified at the same time. The specified cross-sectional deformation amount d1 may be added to the above-described geometric position along the radius of curvature direction, that is, the bending direction. When the cross-sectional deformation amount d1 is added to the geometric position in this way, the actual processing position of the movable die 13 can be specified. This actual machining position is determined by the machine coordinate system xy as described above.
It may be represented by an x coordinate value or a y coordinate value according to z, or may be represented by a difference value from a geometric position based on the barycentric line 59.

In particular, in the case of the hollow long material 11, the fixed mold 12
When bending deformation is caused between the movable mold 13 and the movable mold 13, a cross-sectional deformation occurs at the outlet of the fixed mold 12 side through hole 24. Such cross-sectional deformation includes, besides the above-described depression 104, crushing of a cross section along the radius direction of curvature.
While such cross-sectional deformation is caused, the movable mold 13
Does not cause sufficient plastic bending deformation in the long material 11. Therefore, sufficient bending deformation cannot be caused between the fixed mold 12 and the movable mold 13 according to the geometrical positional relationship based on the shape data, and a shape error occurs in the long product 51 after processing. The movable mold 13 according to the sectional deformation amount d1 derived as described above.
If the actual machining position is specified, the shape error of the long product 51 due to such cross-sectional deformation can be sufficiently eliminated.

Here, the sectional deformation amount d1 is, for example, as shown in FIG.
As shown in the above, it may be specified based on the actually measured data. According to the measured data,

[0116]

(Equation 13)

The section deformation d1 [mm] can be calculated according to the following equation. Here, the coefficient K3 indicates a proportional coefficient calculated based on the actually measured data.

In obtaining such actual measurement data, the long material 11 specified by various cross-sectional shapes, materials, and sizes may be actually processed by the push-through bending machine 10. At this time, the cross-sectional shape of the long material 11 is measured at the outlet of the fixed mold 12 side through hole 24. When the actually measured cross-sectional deformation amount d1 is plotted against the load F, FIG.
Can be obtained. Here, the cross-sectional deformation amount d1 was actually measured for two types of aluminum materials (JIS6063-T1 and JIS6063-T5). In the actual measurement, three approach distances L = 60 mm, 90 between the fixed mold 12 and the movable mold 13
mm and 133 mm were set. According to the actual measurement data, the same coefficient K is used in calculating the cross-sectional deformation amount d1 regardless of the cross-sectional shape and material characteristics of the long material 11.
It is clear that 3 can be used.

Further, as shown in FIG. 42, for example, the NC machining program creation software uses the clearance d of the long material 11 with respect to the fixed mold 12 and the movable mold 13.
2, that is, the clearance amount due to backlash may be specified. The specified clearance amount d2 may be added to the above-described geometric position along the radius of curvature direction, that is, the bending direction. When the clearance amount d2 is added to the geometric position in this way, the actual processing position of the movable mold 13 can be specified. The actual machining position may be represented by an x-coordinate value or a y-coordinate value in accordance with the machine coordinate system xyz, as described above, or may be represented by a difference value from a geometric position based on the barycentric line 59.

The clearance amount d2 [mm] may be specified based on the actually measured value. To obtain the actual measurement values, the long material 11 specified by various cross-sectional shapes, materials, and sizes may be actually processed by the press-through bending machine 10. At this time, the moving distance of the movable mold 13 is measured from when the movable mold 13 starts to move until the long material 11 contacts the fixed mold 12 side through-hole 24. The clearance amount d2 can be specified by the movement distance thus measured. For example, it is desirable that the clearance amount d2 is classified according to the size of the dimensional tolerance of the long material 11. That is, prior to the actual measurement of the clearance amount d2, the external dimensions of the long material 11 are actually measured. The clearance amount d2 of the long material 11 is actually measured for each measured external dimension.

In general, the dimensional accuracy of the long material 11 is allowed within a predetermined range of tolerance, that is, variation. Regardless of these tolerances, the through holes 24, 2
In order to allow the long material 11 to pass through 8 reliably, it is necessary to provide a clearance, that is, a play between the design dimensions of the long material 11 and the dimensions of the through holes 24 and 28. Even if there is no tolerance, in order to allow the long material 11 to pass smoothly through the through holes 24 and 28 of the fixed mold 12 and the movable mold 13, the outer shape of the long material 11 and the It is necessary to provide a clearance, that is, a play between the inner surface and the inner surface.
Until the clearance is eliminated and the fixed mold 12 or the movable mold 13 completely contacts the long material 11, even if the movable mold 13 moves, the long material 11 does not substantially bend and deform. Therefore, sufficient bending deformation cannot be caused between the fixed mold 12 and the movable mold 13 according to the geometrical positional relationship based on the shape data, and a shape error occurs in the long product 51 after processing. If the actual processing position of the movable die 13 is specified according to the clearance amount d2 derived as described above, the shape error of the long product 51 due to such clearance, that is, play, can be sufficiently eliminated. However, the clearance amount d2 used to specify the actual machining position needs to represent the sum of the two clearance amounts generated by the fixed mold 12 and the movable mold 13.

[0122]

As described above, according to the present invention, a long material is twisted at different torsion angles along the axis by using a pair of dies that relatively rotate around the axis of the long material. Can be applied.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing an entire configuration of a push-through bending machine.

FIG. 2 is an enlarged front view of a fixed type.

FIG. 3 is an enlarged front view of a movable type.

FIG. 4 is a schematic diagram schematically showing an entire configuration of a push-through bending system.

FIG. 5 is a perspective view of a fixed type illustrating a concept of a machine coordinate system.

FIG. 6 is a perspective view schematically showing the structure of a long product.

FIG. 7 is a diagram showing a specific example of an NC machining program.

FIG. 8 is a plan view showing a cross-sectional shape of a long product represented by two-dimensional data.

FIG. 9 is a conceptual diagram showing a ridge line of a long product represented by three-dimensional data.

FIG. 10 is a conceptual diagram showing a barycentric line, that is, an axis center specified based on two guide lines.

FIG. 11 is a conceptual diagram showing a barycentric line, that is, an axis, representing the degree of bending of a long product.

FIG. 12 is a conceptual diagram showing control points specified on a barycentric line.

FIG. 13 is a perspective view showing a machine coordinate system associated with each section of the long product.

FIG. 14 is a conceptual diagram showing a cross section of a long product specified based on the center of gravity line.

FIG. 15 is a diagram schematically showing a GUI (graphical user interface) used for setting the orientation of a machine coordinate system with respect to a cross section.

FIG. 16 is a conceptual diagram showing a position of a movable die specified based on a barycentric line.

FIG. 17 is a conceptual diagram showing a process of calculating a y coordinate value from a long product projected on a yz plane.

FIG. 18 is a conceptual diagram showing a process of calculating an x coordinate value from a long product projected on an xz plane.

FIG. 19 is a diagram showing the principle of calculating the twist of a long product between adjacent cross sections.

FIG. 20 is a graph showing a distribution curve for specifying a variation in the relative twist angle around the axis along the axial direction of the long product.

FIG. 21 is a graph showing a distribution curve redrawn with a simple increase curve and a simple decrease curve.

FIG. 22 is a graph showing the principle of redrawing a distribution curve according to the processing characteristics of a push-through bending machine.

FIG. 23 shows a fixed z based on a drawn distribution curve.
5 is a graph showing a principle of calculating a rotation angle around an axis.

FIG. 24 is a graph showing a twist angle of a long material twisted between a fixed type and a movable type.

FIG. 25 is a graph showing a distribution of a specific twist angle of a long material twisted between a fixed type and a movable type.

FIG. 26 is a graph showing a distribution of a specific twist angle of a long material after being sent at a minute distance D1 in the axial direction.

FIG. 27 is a graph showing a distribution of a specific twist angle of a long material after being sent again at a minute distance D2 in the axial direction.

FIG. 28 is a graph showing a torsion angle of a long material that is sent at a minute distance D1 in the axial direction after being twisted between a fixed mold and a movable mold.

FIG. 29 is a graph showing a distribution of a specific torsion angle of a long material that is twisted between a fixed mold and a movable mold and sent at a minute distance D1 in the axial direction.

FIG. 30 is a graph showing a distribution of a specific twist angle of a long material twisted between a fixed mold and a movable mold after being sent at a minute distance D1.

FIG. 31 is a graph showing the distribution of the specific torsion angle of a long material twisted between a fixed mold and a movable mold after being sent again at a minute distance D2.

FIG. 32 is a partially enlarged side view of a long product showing a center of gravity axis and a neutral axis specified between adjacent cross sections.

FIG. 33 is a conceptual diagram showing the relationship between the load applied to the movable mold and the inclination angle of the movable mold.

FIG. 34 is a diagram showing a nominal stress distribution and a nominal strain distribution of a long material.

FIG. 35 is a conceptual diagram showing a step of calculating an approximate curve of a stress-strain curve.

FIG. 36 is a graph showing the relationship between the tilt angle of the movable mold and the rate of movement of the neutral axis.

FIG. 37 is a conceptual diagram showing a step of calculating an elastic-plastic bending deformation amount.

FIG. 38 is a conceptual diagram of the amount of angle around the outlet caused by shear deformation and cross-sectional deformation.

FIG. 39 is a graph showing actually measured data of the angle around the exit.

FIG. 40 is a conceptual diagram of a cross-sectional deformation amount.

FIG. 41 is a graph showing measured data of a cross-sectional deformation amount.

FIG. 42 is a conceptual diagram of clearance, that is, play.

[Explanation of symbols]

10 Press-through bending machine, 11 Long material (profile), 1
2 Fixed type as first type, 13 Movable type as second type, 43 Computer device, 44 Floppy disk (FD) as recording medium, 45 Compact disk (CD) as recording medium, 51 Long product, 59
Center of gravity line as an axis, 71 distribution curve, 71a distribution curve reaching the maximum value, 71b distribution curve passing the maximum value,
72 maximum value, 75 maximum value, 76 minimum value, 85 straight line, L approach distance, ψ specific torsion angle.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G05B 19/4097 G05B 19/4097 Z (72) Inventor Hideo Miwa 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Inside Honda Engineering Co., Ltd. (72) Inventor Yoshihiro Kageyama 1-10-1 Shinsayama, Sayama-shi, Saitama F-term inside Honda Engineering Co., Ltd. (reference) 4E063 AA08 BC15 FA05 JA10 LA17 LA20 5H269 AB01 BB03 NN16 QA09

Claims (8)

[Claims] 1. A step of obtaining shape data representing a shape of a long product twisted around an axis, and a twist angle around the axis per unit feed amount specified in the axial direction based on the shape data. And a step of calculating the torsion angle around the axis of the long product between the first and second molds that relatively rotate around the axis based on the calculated relative twist angle around the axis. A method for creating control data for twisting, characterized in that: 2. The method according to claim 1, wherein, when calculating the torsion angle around the axis, a distribution indicating a variation of the torsion angle around the axis along the axis direction. A step of specifying a curve, a step of detecting a maximum value of the relative twist angle around the axis on the distribution curve, and a first and a second value of the relative twist angle around the axis specified on the distribution curve reaching the maximum value. Multiplying an approach distance measured between the dies. 3. The method for creating control data for twisting according to claim 2, wherein a maximum value and a minimum value adjacent to the maximum value are averaged in the distribution curve, and the distribution curve reaching the maximum value is simple. A method for creating control data for twisting, characterized by being redrawn in an increasing curve. 4. The method for creating control data for twisting according to claim 2, wherein the twist angle around the axis is calculated over the approach distance based on the distribution curve passing through the maximum value. A method for creating control data for twisting, further comprising a step of calculating an integral value of a twist angle around the axis. 5. The twist control data creating method according to claim 4, wherein a maximum value and a minimum value adjacent to the maximum value are averaged in the distribution curve, and the distribution curve passing through the maximum value is A method for creating control data for twisting, characterized by being redrawn in a simple decreasing curve. 6. The twist control data creating method according to claim 2, wherein the distribution curve sandwiching the maximum value is a straight line indicating a uniform twist ratio around the axis center at least over the approach distance. A method for creating control data for twisting, characterized in that the control data is redrawn. 7. The method according to claim 1, wherein said shape data is fetched from a computer-aided design system. 8. A step of obtaining shape data representing the shape of a long product twisted around the axis, and a twist angle around the axis per unit feed amount specified in the axial direction based on the shape data. And calculating the twist angle around the axis of the long product between the first and second molds that relatively rotate around the axis based on the calculated relative twist angle around the axis. A computer-readable recording medium on which a program to be realized is recorded.