JP2010142817A - Simulation system of three-dimensional bending work of tubular body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simulation system of three-dimensional bending work of a tubular body by which computation time is shortened and design change is achieved by accurately determining whether interference with obstacles exists. <P>SOLUTION: The simulation of bending work is performed by calculating the three-dimensional coordinates of the X-, the Y- and the Z-axes by using data including the cutting length, feed length, a rotation angle, a bending angle, bending circular arc length and a bending radius of the tubular body at every bending point of the tubular body by the working motion of a bending machine and also the feed length, the rotation angle and the bending angle are respectively converted into their coordinates in the parallel displacement, the rotation of the coordinate axis around a first axis sharing the original point and the rotation of the coordinate axis around a second axis sharing the original point and the bending simulation is performed while calculating the coordinate of a nodal point as well as the actual length of the tubular body. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention reproduces the processing operation of a bending machine that forms a tubular body into a three-dimensional bending shape, thereby existing in the periphery of the tubular body that is three-dimensionally bent by the processing operation. The present invention relates to a tubular body three-dimensional bending simulation system for determining whether or not interference occurs with a peripheral member.

When bending a long object such as a rod or pipe, if there are multiple bending points on a single long object and it is not on the same plane and has a complicated three-dimensional shape, the material being bent It was difficult to ascertain the passage route, and at the factory level, bending was performed with an actual machine to check whether there was any actual interference with the obstacle or the product being bent. For this reason, it took a long time to determine whether or not bending is possible.
Therefore, conventionally, Patent Documents 1 and 2 that perform interference check by performing bending simulation are known.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-14972) approximates the shape of a peripheral member existing at least around a tube to be bent among a plurality of members constituting a bending machine using a polygon. Display the machining data representing the machining operation amount for determining the machining operation of the bending machine, and approximate the shape of the tube that changes with the machining operation based on the machining data using a straight line The presence or absence of interference between the peripheral member approximated using the polygon and the tube approximated using the straight line, and the surface formed in relation to the approximation by the polygon This is an invention in which a determination is made based on the presence or absence of an intersection with a straight line, and if there is interference between the peripheral member and the tubular body by the determination, a site where the interference has occurred is displayed.

  Patent Document 2 (Japanese Patent Laid-Open No. 1-95819) discloses a computer incorporating CAD data, and an interactive terminal that is placed on a work base remote from the computer and connected to the computer online. And a piping processing machine, the computer selects the corresponding graphic data based on the figure number input at the terminal, based on the specification data of the piping input at the terminal, A modified CAM data is created when the corresponding graphic data corresponding to the figure number is changed, a machining procedure is determined based on the CAM data, and a pipe bending simulation is performed based on the obtained machining procedure. The pipe processing machine is controlled based on the CAM data determined not to cause interference in the simulation. It is.

In the inventions disclosed in Patent Documents 1 and 2, the bending process of the tubular body is three-dimensionally displayed based on the design data of the tubular body bending product or the processing data created from the design data.
As shown in FIG. 12, the design data represents the shape of a three-dimensionally bent tube composed of an x-coordinate, a y-coordinate, a z-coordinate, and a bending radius r, and from the point P1 as the tip. Bending points (nodes) P2, P3, and P4 are set up to the point P5 as the end point. Then, the pipe body is formed into a three-dimensional shape by being bent at the bending radii R1, R2, and R3 at the bending points P2, P3, and P4.

  On the other hand, the machining data shown in FIG. 13 includes feed, rotation, and bending, which are elements of the machining operation, in addition to the x coordinate, the y coordinate, the z coordinate, and the bending radius r. The feed length in the figure represents the length of the linear element excluding the bent portion from the actual length. The rotation angle represents an angle difference between the normals of the two surfaces determined including the bent portion. Further, the bending angle represents a complementary angle with respect to an angle formed by three points including the bending point.

JP 2007-14972 A JP-A-1-95819

  However, in the invention disclosed in Patent Document 1, since the simulation is performed using the machining data automatically created based on the design data, the simulation takes time due to an increase in data capacity and calculation amount. . In the invention disclosed in Patent Document 2, the machining process is displayed as a moving image, which increases the data capacity, and thus requires time for simulation.

Furthermore, neither Patent Document 1 nor Patent Document 2 considers the flange of the tube, and since it is not simulated in a form close to the actual machine, the accuracy of the interference check cannot be sufficient, and the elongation when the tube is bent is not considered. Since the interference check is performed as it is, the apex position of the bent portion of the tubular body cannot be obtained accurately, and there is a possibility that it interferes with an obstacle when actually placing the tubular body on the site.
In addition, since there is no approach when machining data is given as design data, it is difficult to determine how to change the design when a design change occurs.

  Therefore, in view of the problems of the prior art, the present invention provides a three-dimensional bending simulation system for a tubular body capable of reducing calculation time and making a design change by accurately determining the presence or absence of interference with an obstacle. The task is to do.

  In order to solve such a problem, by reproducing the processing operation of a bending machine for forming a tubular body into a three-dimensional bending shape, the tubular body that has been three-dimensionally bent by the processing operation and the same tubular body In the tubular body three-dimensional bending simulation system for confirming whether or not there is interference with peripheral members existing in the periphery, the cutting length and feed of the tubular body at each bending point of the tubular body by the machining operation. Using the data composed of the length, rotation angle, bending angle, bending arc length, and bending radius, the three-dimensional coordinates of the X, Y, and Z axes are calculated to perform a bending simulation, and the feed length, rotation angle, The bend angle is translated into parallel translation, rotation of the coordinate axis around the axis of the first axis sharing the origin, and rotation of the coordinate axis around the axis of the second axis sharing the origin, along with the actual length of the tube Tip coordinates and nodes And performing the machining simulation bending while calculating the coordinates.

According to this invention, the feed length, the rotation angle, and the bending angle are each translated, the rotation of the coordinate axis around the axis of the first axis sharing the origin, and the coordinate axis around the axis of the second axis sharing the origin By performing the bending simulation while calculating the tip and nodal coordinates along with the actual length of the tube, it can be calculated according to the procedure of the bending operation. Since the machining operation can also be expressed by coordinate conversion, even when a design change occurs, it is possible to obtain the degree of bending up to which angle.
In addition, since the number of bending angle and rotation angle divisions can be easily increased, the accuracy of interference determination is increased.

The feeding length is set at a bending point of the tubular body in consideration of an offset amount with respect to an axis when the tubular body is bent.
Thereby, the vertex coordinates (node coordinates) and the tip coordinates of the bending point can be accurately obtained in consideration of the elongation at the time of bending of the tubular body, and each vertex coordinate can be calculated.

In addition, the tubular body is simulated as a straight line, and a flange provided on the tubular body as a disk, and the shape of peripheral members existing around the tubular body is approximated and displayed using polygons and cylinders. And
Thereby, since a bending machine etc. can be simulated in the form close | similar to a real machine, the presence or absence of the interference of a pipe body and a bending machine can be determined. Therefore, the accuracy of the interference check is improved.
In addition, the peripheral member which cannot be expressed with a polygon includes, for example, a flange provided on a pipe body in addition to a bending machine.

Further, the determination of the presence or absence of interference between the tubular body and the peripheral members existing around the tubular body is performed for the feeding length, the rotation angle, and the bending angle of the tubular body at the nodes calculated by the coordinate transformation, respectively. It is performed.
Thus, by determining whether or not there is interference with respect to the feed length, rotation angle, and bending angle of the tube at the node, it is easy to make a plan for how to change the design even when a design change occurs.

Further, the determination of the presence or absence of the interference is to confirm whether there is a node in the peripheral member, and to check whether there is a peripheral member in a line segment connecting the nodes; And confirming whether or not the distance between the peripheral member and the line segment connecting the nodes is within the radius of the tubular body.
As a result, the presence or absence of interference between the tubular body and the peripheral members existing around the tubular body can determine the intersection point from the positional relationship between each vertex of the node, tip, and end and the surface, and there is interference. Is determined, the calculation time is shortened by not having to execute the next step.

In addition, the interference part, operation, and angle where the interference between the tube and the peripheral member is displayed, and the rotation angle and the bending angle of the pipe body are gradually changed in the direction in which the coordinates of the interference part are reversed or separated from the peripheral member. It is characterized by changing.
In this way, by reversing the rotation angle and bending angle of the tubular body in the direction of reversing the coordinates of the interference site or separating the interference site from the peripheral member, a shape avoiding interference can be obtained. Even if interference occurs in the middle of the process, it is possible to automatically perform simulations with different processing methods, such as bending from the opposite direction by displaying the interference site, motion, and angle, and executing simulation for the specified number of bendings. It becomes possible.

Furthermore, the interference part, operation | movement, and angle which the interference with the said pipe body and the peripheral member produced are displayed, The flange which exists in the said interference part and is provided in a pipe body is removed, It is characterized by the above-mentioned.
As a procedure for bending the tubular body, first, the tubular body is bent from the front or from the back with the flanges provided. If interference occurs at this time, the flange is then removed and the tube is bent. In this way, for example, when flanges are provided at both ends of the pipe body, the simulation is automatically performed so as to avoid interference by removing the flanges in the order of the front end and the rear end and changing the processing procedure step by step. Thus, it is possible to execute a simulation for a specified number of bending times.

  ADVANTAGE OF THE INVENTION According to this invention, while shortening calculation time, the presence or absence of the interference with an obstacle can be determined accurately and a 3D bending simulation system of a tubular body can be provided.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.
Here, the pipe body to be three-dimensionally bent is a long object such as a bar or a pipe, and includes a long object with a flange or a sleeve. In addition, examples of the peripheral member existing around the tube include a wall, a ceiling, a floor, a bending machine, and other equipment, and are referred to as an obstacle in this embodiment.

First, the coordinate expression of the tube will be described with reference to FIG. FIG. 1 shows the initial state of the tube in the 0-XYZ coordinate system.
The initial state of the tube before bending is expressed as follows.
Tip coordinates (subscript: p) = origin → (x _p , y _p , z _p ) = (0, 0, 0)
End coordinates (subscript: e) = on the X axis → (x _e , y _e , z _e ) = (L, 0, 0)
However, z _p and z _e = 0 are set for simplification.

Here, the tip refers to the bending side, and the other end is the end. L is the cut length of the tube, and other than the tip and end coordinates. Further, the node coordinates (subscript: n) are (x _n , y _n , z _n ) as coordinates indicating the position to bend in addition to the front end coordinates and the end coordinates.

Next, details of the bending operation and corresponding coordinate transformation will be described below with reference to FIGS.
There are two operations required to bend the tube with a bending machine, such as (A) sending the tube to a bending position and (B) bending the tube. When this bending operation is made to correspond to the coordinate transformation on the Cartesian coordinate system, the motion (A) is mathematically translated as the tube moves in the X-axis direction, and the motion (B) is rotated around the Z-axis. Can be expressed. This operation is shown in FIGS. 2A and 2B, and operations (A) and (B) are represented by arrows A and B. FIG.
However, the translation is always in the negative direction of the X axis, and the bending angle due to the rotation around the Z axis, that is, the bending of the tube, can be in the range of 0 <t ≦ π (rad).

Further, when the number of times of bending of the tubular body is two times or more, the tubular body is rotated after the feeding operation of (A) described above, and then the bending operation of (B) is performed (FIGS. 3A to 3C). )reference). By this rotation operation, the tip position of the tube body is determined. When the rotation operation for determining the tip position of the tubular body is taken as (B) ′ and corresponds to the coordinate transformation on the orthogonal coordinate system, the operation (B) ′ can be expressed as rotation around the X axis. This operation is indicated by an arrow B ′ as shown in FIG. Note that the rotation angle due to the rotation around the X axis can be in the range of 0 ≦ t _d ≦ 2π.

Therefore, the coordinate conversion corresponding to the second and subsequent bending operations from the first bending is as follows.
-First bending (A) Parallel movement of the tube in the X-axis direction (B) Rotation around the Z-axis-Second and subsequent bending operations (A) Parallel movement of the tube in the X-axis direction (B) 'Rotation around X-axis (B) Rotation around Z-axis Hereinafter, coordinate conversion corresponding to the first bending process and the second and subsequent bending processes will be described.

(Coordinate transformation corresponding to the first bending)
The coordinates (x ′ _pa , y ′ _pa ) after the tip coordinates (x _p , y _p , z _p ) of the tube are translated in the X axis direction by (x ′ _a , y ′ _a , z ′ _a ) , Z ′ _pa ) is as follows:

Further, the bending process is bent along the bending machine piece. The frame part is simulated by a cylinder as indicated by reference numeral 1 in FIG. The point on the circular arc of the cylinder can be expressed as follows according to the bending angle. The coordinates of the points on the arc shown in FIG. 4 are (x _s , y _s , z _s ), and t represents a predetermined final bending angle.

Since the tubular body is bent along the top part, the tubular body extends along the arc length. In other words, when bending with respect to the origin, the length from the origin to the tip in the initial state is always equal to the length from the point on the arc in the middle of bending (subscript: s) to the tip coordinates. From this, the tube can be further translated in parallel so that the point on the arc is the origin, and the tube can be bent around the Z axis to express the bending of the tube (clockwise). Positive). First, the tip coordinates after the coordinate axes of the orthogonal coordinate system 0-XYZ are translated so that the point on the arc is the origin are as follows.

となることから、曲げ途中を含む曲げ時の管体の先端座標（ｘ’_ｐ，ｙ’_ｐ，ｚ’_ｐ）は次式のように表すことができる。

なお、右肩記号Ｔは転置を表す。 Next, a bending operation will be considered. In the bending operation, the tube in the Cartesian coordinate system 0-XYZ, which is translated so that the point on the arc is the origin, shares the origin and rotates around the Z axis by t _k (a positive angle clockwise). This is equivalent to considering the position in the 0-X′Y′Z ′ coordinate system. The coordinate transformation matrix T ₁ from the 0-XYZ coordinate component to the 0-X′Y′Z ′ coordinate component is

Therefore, the tip coordinates (x ′ _p , y ′ _p , z ′ _p ) of the tubular body during bending including the middle of bending can be expressed as the following equation.

The right shoulder symbol T represents transposition.

A straight line connecting the tip coordinates calculated in this way and a point on the arc is a tangent to the circle. Therefore, the intersection point where the tangent line and the X axis intersect is defined as a node coordinate n1.

(Coordinate conversion corresponding to the second and subsequent bending)
Similarly to the coordinate conversion corresponding to the first bending process, the tip coordinates after the parallel movement of the tube are expressed as follows.

と表すことができる。
よって、Ｘ軸まわりの回転後の先端座標は以下のようになる。

Rotation around the X axis to determine the tube tip position (rotational operation), i.e., the coordinate conversion 'to coordinate components 0-X'0-X'Y'Z to _{d Y 'd Z' d} coordinate component , The matrix T _d2 is

It can be expressed as.
Therefore, the tip coordinates after rotation around the X axis are as follows.

ただし、曲げ途中の先端座標を示す（ｘ”_ｔ，ｙ”_ｔ，ｚ”_ｔ）は次式となる。

となる。 Furthermore, the tip coordinates at the time of bending including the middle of bending of the tube body are

However, (x ″ _t , y ″ _t , z ″ _t ) indicating the tip coordinates during bending is expressed by the following equation.

It becomes.

Also for the second and subsequent bending processes, the tip, end, and node coordinates can be calculated by repeatedly using coordinate transformation as described above.
Here, the tip, end, and other nodes ni (i = 1, 2, 3) of the tube body bent three times can be expressed by the following equations. As shown in FIG. 5, i is 1, 2,...

節点座標は、先端座標に近いｎ１、ｎ２に関しては、先端座標と同様にして求めることができる。

Since the end coordinates move on the X axis,

The node coordinates can be obtained in the same manner as the tip coordinates for n1 and n2 close to the tip coordinates.

また、節点座標ｎ３は曲げ位置であることから原点となる。

Since the node coordinate n3 is an intersection of the node coordinate n2 and the X axis of a straight line passing through a point on the arc (subscript: s),

The node coordinate n3 is the bending position, and thus becomes the origin.

FIG. 6 is a flowchart of the coordinate conversion corresponding to the bending operation described above.
That is, when coordinate conversion is started in step S1, the following procedure is looped with the number of bendings being n in step S2. In step S3, the tube is translated in the X-axis direction. In step S4, it is determined whether or not there is a rotating operation. If there is a rotation operation, the coordinate system is rotated around the X axis by a predetermined angle in step S5. If there is no rotation operation, step S5 is not performed.

Then, the presence or absence of a bending operation is determined in step S6. If there is a bending operation, the Y axis is translated in consideration of the bending radius and angle in step S7, and the coordinate system is rotated by a predetermined angle around the Z axis in step S8. If there is no bending operation, steps S7 and S8 are not performed.
When the procedure is looped up to n times of bending, the loop is terminated in step S9, and the coordinate conversion is terminated in step S10.

In this way, calculation can be performed according to the procedure of bending operation, and a series of processing operations such as feeding, rotating, and bending of the tube can be made to correspond to coordinate conversion on the Cartesian coordinate system. Even if a change occurs, you can see how much angle you can bend. In addition, the number of bending angle and rotation angle divisions can be easily increased, and the accuracy of interference determination is increased. Furthermore, the number of divisions can be increased only when approaching an obstacle to speed up the calculation.
In addition, since the rotation direction of the rotation direction can be either clockwise or counterclockwise, interference can be prevented.

Next, a simulation is performed in order to check the interference due to bending of the tubular body by expressing the obtained orthogonal coordinate system. This flowchart is shown in FIG.
When the simulation is started in step S11, the conventional design data is read in step S12, and the tubular body and the obstacle are expressed in an orthogonal coordinate system in step S13 (see FIG. 6).

Next, a processing procedure method is selected in step S14. The number of processing procedures for bending the tube varies depending on the flange provided on the tube. For example, when the flange is attached to both ends, there are eight types, which are shown as processing procedures 1 to 8 below.
Processing procedure 1: Bend from the front with the flange attached.
Processing procedure 2: Bend later with the flange attached.
Processing procedure 3: Remove the front flange and bend from the front.
Processing procedure 4: Remove the front flange and bend it later.
Processing procedure 5: Remove the rear flange and bend from the front.
Processing procedure 6: The rear flange is removed and bent later.
Processing procedure 7: Remove both flanges (without flange) and bend from the front.
Processing procedure 8: Remove both flanges (without flange) and bend them later.
In step S14, these processing procedures are selected in order from processing procedure 1.

  For the processing procedure selected in step S14, loop 1 to be described later is repeated with n times of bending in step S15. First, in step S16, it is determined whether or not there is a tube feeding operation. If it is determined that there is a tube feeding operation, a predetermined amount is fed and translated in step S17, and whether or not a rotating operation is performed is determined in step S18. If it is determined that there is a rotating operation, in step S19, the tube is rotated around the X axis by the increment angle and twisted to a predetermined angle. In step S20, an interference check is performed in the rotating operation, and the loop is twisted to a predetermined angle while looping in step S21 (loop 2). If it is determined that there is no rotation operation, steps S19 to S21 are not performed.

  After confirming the presence / absence of the rotation operation, the presence / absence of the bending operation is determined in step S22. If it is determined that there is a bending operation, in step S23, the tube body is rotated around the Z axis by a chopping angle and twisted to a predetermined angle. In step S24, an interference check in the bending operation is performed, and in step S25, the loop is bent to a predetermined angle while being looped (loop 3). If it is determined that there is no bending operation, steps S23 to S25 are not performed.

  In step 26, when steps S16 to S25 are performed, loop 1 is returned to step S15. If it is determined in step S16 that there is no tube feeding operation, steps S16 to S25 are not performed. In this way, when the above procedure is executed up to n times of bending, the loop 1 is terminated in step S26.

Thereafter, in step S27, the presence / absence of interference is determined through all interference checks. If it is determined that there is interference, it is determined in step S28 whether the processing procedure 8 has been completed. If it is determined in step S28 that the machining procedure 8 has not ended, the process returns to step S14 to select the next machining procedure. On the other hand, if it is determined in step S27 that there is no interference, or if it is determined in step S28 that the processing procedure 8 has been completed, the simulation is terminated in step S29.
In this way, the interference check can be performed by rotating the loop in order from the processing procedure 1. The simulation ends when there is no interference through all interference checks. However, the simulation can be ended regardless of the presence or absence of interference when the loop is turned to the processing procedure 8 in a state where no flange is provided.

The interference check described above can be confirmed by determining the presence or absence of an intersection from the positional relationship between the surface of the obstacle and each of the tip, node, and terminal points.
There are two situations for the interference problem between the tube and the obstacle. (I) Can the tube be set at a predetermined position, or (ii) After setting the tube at a predetermined position, It can be twisted or bent to a predetermined angle. It is common that both (i) and (ii) occur when the pipe body is bent twice or more, and the problem is whether the bent portion interferes with the bending machine. It is simply the difference between interference before bending or interference during bending. That is, whether or not interference occurs can be determined by determining in the order of (i) and (ii).

Furthermore, when the interference situation of (i) and (ii) is described in detail, it can be classified into the following three interference patterns.
1) Tip coordinates or node coordinates exist inside the obstacle.
2) Although there are no tip coordinates and nodal coordinates, the line segment between the nodes passes through the inside of the obstacle.
3) The distance between the obstacle closest to each node and the central axis of the tube is smaller than the radius of the tube, or a flange attached to the tip is present in the obstacle.

The presence or absence of interference is confirmed in the order of 1) to 3). The confirmation procedure for the presence or absence of interference will be described with reference to FIGS. In FIG. 8, the description is focused on the nodes, but the check is performed with the tip and end taken into consideration in the same way as the nodes. Reference numeral 10 in FIG. 9 is an obstacle.
First, as shown in FIG. 8, when the interference check is started in step S31, it is determined in step S33 whether or not there is a node in the obstacle (FIG. 9A). If it is determined that there is no node in the obstacle, it is determined in step S34 whether or not a line segment connecting the nodes exists in the obstacle (FIG. 9B).

When it is determined that the line segment does not exist in the obstacle, it is determined in step S35 whether the distance between the obstacle and the line segment is smaller than the radius r of the tubular body (FIG. 9C). If it is determined that the distance between the obstacle and the line segment is smaller than the radius r of the tube, the process returns to step S32 to loop the above-described procedure by the number of divisions of a predetermined angle, and the loop is terminated in step S36. In step S37, the interference check is terminated.
Although not shown, in step S35, it may be determined whether or not the flange attached to the tip exists in the obstacle as in the interference pattern 3) described above. At that time, if it is determined that the flange attached to the tip does not exist in the obstacle, the same loop is performed.

If it is determined in step S33 that a node is present in the obstacle, if it is determined in step S34 that a line segment connecting the nodes exists in the obstacle, the distance between the obstacle and the line segment is determined in step S35. Is within the radius r of the pipe, or the flange attached to the tip is present in the obstacle, in step S38, the tube body is engraved so as to reach a predetermined angle, and the rotation operation or bending operation is performed. Perform (see FIG. 7).
If it is determined in step S38 that the predetermined angle has not been reached, the process returns to the previous stage of step S32 and the above-described procedure is performed. If it is determined that the predetermined angle has been reached, the interference check is terminated in step S37.
In this way, since it can be confirmed by determining the presence / absence of an intersection from the positional relationship between the surface of the obstacle and each of the tip, node, and terminal points, the calculation time is shortened.

  Furthermore, in the simulation of the present embodiment, the axial displacement of the tubular body including elements such as feeding, rotation, and bending of the machining operation, the axial elongation of the tubular body that occurs during bending, and the like are taken into consideration. Each vertex position that does not interfere can be accurately obtained.

Moreover, in this embodiment, even when interference arises, the simulation for n times of the designated bending times can be executed. Here, a case where interference occurs by performing a simulation of interference check of a tube body with the number of bendings n times in the procedure shown in FIG. 7 will be described with reference to FIG.
FIG. 10 includes an obstacle 10 and a tube body 6, and the tube body 6 has a front end 2, a node 4, and a terminal end 8. With such a configuration, the interference site, operation, and angle at which interference has occurred are displayed as simulation results.
FIG. 11 shows a simulation result of the number of bendings 3 times (n = 3). For example, FIG. 11A shows that there is no interference at the end of the third bending time, but the number of bending times 2 is halfway. The case where it is determined that there is interference at the second time is shown.

When it is determined that there is interference during the second bending as described above, it is considered to change the design of the second bending angle.
Here, the second bending is reversed as shown in FIG. Therefore, it is determined that there is no interference in both the second and third bendings, and the target shape can be obtained. In this way, even when interference occurs, the target shape can be made without interference by changing the bending angle, reversing the bending, or removing the flange to change the processing method during processing. it can. In addition, by knowing how many times the rotation interferes during bending, it is possible to easily determine how to change the bending angle of the interfering bending point.

At this time, if the angle is shifted little by little and calculated, interference can be checked every time a curve is made. In this embodiment, it is not necessary to store all coordinate values, and it is sufficient to store only the coordinate point of the previous bend, so there is very little data to be stored, and the calculation speed can be shortened.
Even if interference occurs in the middle of the process in this way, simulations with different processing methods, such as bending from the opposite direction, removing the flange, and removing the flange, are automatically performed by displaying the interference site, motion, and angle. The simulation for the specified number of bendings is executed.

Further, although the simulation described above is performed by approximation using a polygon as an obstacle, in the present embodiment, it can be approximated by using a cylinder. As shown in FIG. 11, the bending machine 12 and the flange 14 cannot be expressed by polygons, but can be simulated to a shape close to an actual machine by using a cylinder. Reference numeral 6 denotes a tubular body. Here, the flange 14 obtains a plane in which the tubular straight portion passing through the tip coordinates is a perpendicular line, and calculates a circle from which the tip coordinates are the center of the circle.
Therefore, by making the shape of the peripheral member that cannot be expressed in a polygon as a cylinder, it is possible to simulate a bending machine, flange, etc. in a shape closer to the actual machine, so the accuracy of interference check between the tube and the obstacle is high. It is higher than when only the square is used.

  According to the present invention, the calculation time can be shortened and the design can be changed by accurately determining the presence or absence of interference with an obstacle, which is advantageous when applied to a three-dimensional bending simulation system for a tubular body. .

It is a figure which shows the initial state of a tubular body in a 0-XYZ coordinate system. It is a figure explaining the coordinate conversion of the 1st bending process, (a) shows a parallel movement, (b) shows the rotation around a Z-axis. It is a figure explaining the coordinate conversion of the 2nd bending process, (a) shows a parallel movement, (b) shows the rotation around the X-axis, (c) shows the rotation around the Z-axis. It is a figure explaining the bending process of the pipe body in a bending machine top part. It is explanatory drawing of the coordinate at the time of 3 times bending. It is a flowchart about the coordinate transformation corresponding to the bending operation of a tubular body. It is a flowchart about a tubular body bending interference check. It is a flowchart about the logic for pipe bending interference check. It is a figure explaining a tubular body bending interference check. It is a figure explaining a simulation result and interference avoidance. It is a simulation result when an obstacle is approximated by a cylinder. It is a figure which shows the conventional design data. It is a figure which shows the conventional process data.

Explanation of symbols

1 Frame 2 End 4 Node 6 Tubing 8 End 10 Obstacle 12 Bending Machine 14 Flange

Claims (7)

By reproducing the processing operation of a bending machine that forms a tubular body into a three-dimensional bending shape, a tubular body that is three-dimensionally bent by the processing operation and a peripheral member that exists around the tubular body; In a three-dimensional bending simulation system for a pipe that checks whether or not interference occurs between
Three-dimensional X, Y, and Z axes using data consisting of the cutting length, feed length, rotation angle, bending angle, bending arc length, and bending radius of the tubular body for each bending point of the tubular body by the machining operation. Bending simulation is performed by calculating coordinates, and the feed length, rotation angle, and bending angle are each translated, the rotation of the coordinate axis around the axis of the first axis sharing the origin, and the second sharing the origin A three-dimensional bending simulation system characterized in that a coordinate transformation is performed to rotation of a coordinate axis around an axis of the axis, and a bending simulation is performed while calculating a tip coordinate and a node coordinate together with an actual length of the tubular body.   The three-dimensional bending simulation system according to claim 1, wherein the feed length is set at a bending point of the tubular body in consideration of an offset amount with respect to an axis when the tubular body is bent.   Simulating the tubular body as a straight line and a flange provided on the tubular body as a disk, and displaying the shape of a peripheral member existing around the tubular body by using a polygon and a cylinder. The three-dimensional bending process simulation system according to claim 1.   Determination of the presence or absence of interference between the tubular body and peripheral members existing around the tubular body is performed for the feed length, rotation angle, and bending angle of the tubular body at the node calculated by the coordinate transformation. The three-dimensional bending processing simulation system according to claim 1.   The determination of the presence / absence of the interference includes a step of confirming whether or not a node exists in the peripheral member, a step of confirming whether or not a peripheral member exists in a line segment connecting the nodes, and the peripheral 5. The three-dimensional bending simulation system according to claim 4, further comprising the step of confirming whether a distance between a member and a line segment connecting the nodes is within a radius of the tubular body. .   The interference part where the interference between the tubular body and the peripheral member has occurred, the operation, and the angle are displayed, and the rotation angle and the bending angle of the tubular body are gradually changed in the direction in which the coordinates of the interference part are reversed or separated from the peripheral member The three-dimensional bending processing simulation system according to claim 5.   The three-dimensional bending process according to claim 6, wherein an interference part, an operation, and an angle at which interference between the tubular body and a peripheral member is generated are displayed, and a flange provided on the tubular body that exists in the interference part is removed. Simulation system.

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