JP4984035B2 - Pipe bending condition calculation system, pipe bending condition calculation program, and pipe vendor - Google Patents

Description

  The present invention relates to a pipe bending condition calculation system for providing a bending condition for obtaining a target shape to a pipe vendor, a program for causing a computer to calculate the bending condition, and a bending pipe having a target shape. The pipe vendors belong to the field of computerized metal working technology.

  It is natural for those skilled in the art that when a pipe is bent at a plurality of places (at least one place) to produce a bent pipe having a target shape, it is necessary to consider a springback. When creating a pending pipe with the target shape without considering the springback, the bending pipe in the final form will be farther from the bending pipe with the final shape, especially when there are more bends. For example, the bending pipe is a pipe for hydroforming. If it is put in the mold as, it may not fit in the mold.

  As a countermeasure, there is a method described in Patent Document 1, for example, as a method of calculating bending conditions necessary for obtaining a bending pipe having a target shape in consideration of springback. This method uses a finite element method to calculate bending conditions that take into account springback.

JP 2005-161332 A

  However, in the case of the method of Patent Document 1, since the finite element method is used, it takes time to calculate the bending conditions necessary to obtain a bending pipe having a target shape. If the number is increased, it will take a very long time to calculate each bending condition.

  In addition, in order to calculate the bending conditions corresponding to each bent portion so that each bent portion has a target shape, in the case of a bending pipe having a shape having a large number of bent portions, the processing conditions corresponding to each bent portion are calculated. The allowable calculation error included in the calculation is accumulated, and as a result, a forming pipe that fits the target bending pipe between the calculated overall shape of the bending pipe and the overall shape of the target bending pipe is created. There may be a difference in shape such that the bending pipe calculated in the mold does not fit.

  As a countermeasure to this, it is conceivable that the calculation by the finite element method is performed precisely in order to reduce the influence due to the accumulation of the calculation error, but the calculation requires much time accordingly.

  Therefore, the present invention calculates the optimum bending condition for obtaining a bending pipe having a target shape even in a short time without using the finite element method and even a bending pipe having a large number of bending portions. Pipe bending condition calculation system, pipe bending condition calculation program that allows a computer to calculate the optimal bending condition for obtaining a bending pipe of a target shape, and a bending pipe of a target shape while considering springback It is an object of the present invention to provide a pipe bender that can manufacture the above.

  In order to solve the above problems, the present invention is configured as follows.

ここで、Ｒ’、θ’は、前記加工条件算出手段が算出したスプリングバック後のパイプの曲げ半径及び曲げ角度であり、θａは、同じく加工条件算出手段が算出したスプリングバックの影響を加味して補正した曲げ加工条件としてのパイプの曲げ角度である。 First, the invention according to claim 1 is a pipe bending condition calculation system for calculating bending conditions to be provided to a pipe vendor that performs bending at a plurality of locations of a pipe,
Target shape information acquisition means for obtaining target shape information of a pipe including information on a bending radius and a bending angle of a bent portion;
A comparison point defining means for defining a plurality of comparison points on the center line of the pipe;
Based on the target shape information, processing condition calculation means for calculating bending conditions including a bending radius and a bending angle while taking into account the effect of springback for each bending portion of the pipe;
Processing shape calculation means for calculating the shape of the pipe that is sequentially bent based on the bending processing conditions calculated by the processing condition calculation means for each bending portion;
A positional relationship determining means for determining a positional relationship between a comparison point of a pipe having a target shape and a corresponding comparison point of the calculated shape pipe calculated by the machining shape calculation stage;
The processing condition calculation means uses only the outer diameter d1, the inner diameter d2, the yield stress σy, the Young's modulus E, and the hardening coefficient Eh of the pipe as parameters when calculating the bending processing conditions while taking into account the effect of springback. When the bending angle θ included in the target shape information is corrected based on the following equations 1, 2, and 3, and the determination result of the positional relationship determination means deviates from a predetermined allowable range The correction bending process condition in which the bending radius R included in the target shape information is corrected is calculated so that the determination result falls within the allowable range.

Here, R ′ and θ ′ are the bending radius and bending angle of the pipe after springback calculated by the processing condition calculation means, and θa is also considered by the influence of the springback calculated by the processing condition calculation means. It is the bending angle of the pipe as the bending process condition corrected by the above.

Further, the invention according to claim 2, in the pipe bending condition calculating system according to claim 1, wherein the positional relationship determination means compares the point of the pipe compare points and calculating the shape of the pipe of the corresponding target shape Is determined, it is determined whether or not the distance between the two comparison points exceeds a predetermined allowable range .

ここで、Ｒ’、θ’は、前記加工条件算出手段が算出したスプリングバック後のパイプの曲げ半径及び曲げ角度であり、θａは、同じく加工条件算出手段が算出したスプリングバックの影響を加味して補正した曲げ加工条件としてのパイプの曲げ角度である。 On the other hand, the invention according to claim 3 is a pipe bending condition calculation program for driving a computer to calculate bending conditions to be provided to a pipe vendor that performs bending at a plurality of locations of a pipe,
Computer
Target shape information acquisition means for obtaining target shape information of a pipe including information of a bending radius and a bending angle of a bent portion;
A comparison point defining means for defining a plurality of comparison points on the center line of the pipe;
Based on the target shape information, a processing condition calculation means for calculating a bending processing condition including a bending radius and a bending angle while taking into account the effect of springback for each bending portion of the pipe,
A machining shape calculation means for calculating the shape of a pipe that is sequentially bent based on the bending conditions calculated by the machining condition calculation means for each bending portion, and a comparison point of a pipe having a target shape and the machining shape calculation stage are calculated. Function as a positional relationship determination means for determining the positional relationship with the corresponding comparison point of the calculated shape pipe , and
When functioning as the processing condition calculating means, when calculating bending conditions while taking into account the effect of springback, the outer diameter d1, inner diameter d2, yield stress σy, Young's modulus E, and hardening coefficient Eh of the pipe are used as parameters. The bend angle θ included in the target shape information is corrected based on the following equations 1, 2, and 3, and the determination result of the positional relationship determination means deviates from a predetermined allowable range. In this case, a function is made to calculate a corrected bending process condition in which the bending radius R included in the target shape information is corrected so that the determination result falls within the allowable range.

Here, R ′ and θ ′ are the bending radius and bending angle of the pipe after springback calculated by the processing condition calculation means, and θa is also considered by the influence of the springback calculated by the processing condition calculation means. It is the bending angle of the pipe as the bending process condition corrected by the above.

ここで、Ｒ’、θ’は、前記加工条件算出手段が算出したスプリングバック後のパイプの曲げ半径及び曲げ角度であり、θａは、同じく加工条件算出手段が算出したスプリングバックの影響を加味して補正した曲げ加工条件としてのパイプの曲げ角度である。 The invention according to claim 4 is a pipe bender comprising a pipe bending device for bending a pipe, and bending the pipe at a plurality of locations based on a predetermined bending process condition.
Target shape information acquisition means for obtaining target shape information of a pipe including information on a bending radius and a bending angle of a bent portion;
A comparison point defining means for defining a plurality of comparison points on the center line of the pipe;
Based on the target shape information, processing condition calculation means for calculating bending conditions including a bending radius and a bending angle while taking into account the effect of springback for each bending portion of the pipe;
Processing shape calculation means for calculating the shape of the pipe that is sequentially bent based on the bending processing conditions calculated by the processing condition calculation means for each bending portion;
A positional relationship determining means for determining a positional relationship between a comparison point of a pipe having a target shape and a corresponding comparison point of the calculated shape pipe calculated by the machining shape calculation stage;
The processing condition calculation means uses only the outer diameter d1, the inner diameter d2, the yield stress σy, the Young's modulus E, and the hardening coefficient Eh of the pipe as parameters when calculating the bending processing conditions while taking into account the effect of springback. When the bending angle θ included in the target shape information is corrected based on the following equations 1, 2, and 3, and the determination result of the positional relationship determination means deviates from a predetermined allowable range , Calculating a corrected bending process condition in which the bending radius R included in the target shape information is corrected so that the determination result falls within the allowable range ;
The pipe bending apparatus is characterized in that the pipe is bent based on either the bending condition or the corrected bending condition.

Here, R ′ and θ ′ are the bending radius and bending angle of the pipe after springback calculated by the processing condition calculation means, and θa is also considered by the influence of the springback calculated by the processing condition calculation means. It is the bending angle of the pipe as the bending process condition corrected by the above.

  According to the present invention, as described in claim 1, the pipe center in the calculated shape calculated by taking into account the influence of the springback for each bent portion and the plurality of comparison points provided on the center line of the pipe having the target shape Corrected bending by determining the positional relationship with the corresponding comparison point on the line and correcting the original bending conditions so that the determination result falls within the allowable range when the determination result deviates from the predetermined allowable range By calculating the machining conditions, either the initial bending conditions or the corrected bending conditions are provided to the pipe vendor. As a result, a bent product having a target shape or a shape within an allowable range as compared with the target shape is obtained. Specifically, when comparing the calculated shape calculated from the shape of the pipe that has been sequentially bent while taking into account the effect of springback for each bent portion, the correspondence in the vicinity of the previously formed bent portion Considering that the difference in the positional relationship between the matching points appears in the difference in the positional relationship between the corresponding comparison points in the vicinity of the next formed bent part, the difference in the positional relationship between the corresponding comparison points is acceptable. Since the machining conditions that fall within the range are calculated, the overall shape machined by the calculated bending conditions does not deviate significantly from the target shape. In addition, since the influence of the springback in each bent portion is calculated by, for example, material mechanical calculation with respect to the center line, the calculation time is shortened as compared with the case where the finite element method is used.

In this case, according to the first aspect of the present invention, when the processing condition calculation means calculates the bending processing condition in consideration of the influence of the springback, the conditions include the outer diameter, inner diameter, and yield of the pipe as parameters. It is calculated based on an equation that uses only stress, Young's modulus, and hardening coefficient.

According to the second aspect of the present invention, when the positional relationship determination means determines the positional relationship between the comparison point of the corresponding target-shaped pipe and the comparison point of the calculated-shaped pipe, It is determined whether the distance between the comparison point and the corresponding comparison point of the calculated shape pipe exceeds a predetermined allowable range .

On the other hand, according to the third aspect of the present invention, if the program according to the present invention is installed in a computer and executed, the same effect as the system of the first aspect can be obtained.

Furthermore, according to the invention described in claim 4 , the bending condition is automatically corrected as necessary, and a pipe bender is obtained in which a pipe product having a shape substantially matching the target shape is obtained. .

  First, what the present invention does is to obtain an appropriate pipe bending condition in order to obtain a bending pipe having a target shape. Therefore, in order to understand the present invention, first, a bending process of a pipe, that is, a manufacturing method of a bending pipe will be briefly described.

  FIG. 1 is a diagram schematically showing a configuration of a pipe bender for bending a pipe. A pipe bender indicated by reference numeral 10 in the drawing is roughly a roller-shaped bending die 12, a clamp 16 having a clamper 14 that presses the pipe P against the bending die 12, and the pipe P around the center line of the pipe P. The rotary chuck 18 rotates around the center, the transport mechanism 22 of the pipe P that feeds the pipe P in the feeding direction 20, and a pressing roller 24 for restraining the pipe P during bending. The pipe bender 10 includes an orthogonal coordinate system (hereinafter referred to as a “reference coordinate system”) including three Xa axes, a Ya axis, and a Za axis (an axis extending in a direction orthogonal to the drawing). The direction 20 is the Xa axis direction.

  The bending mold 12 and the clamp 16 function as means for bending the pipe P in cooperation.

  The bending die 12 has a roller shape having a rotation center line orthogonal to the feed direction 20 (in the Za axis direction) and is configured to be rotatable at a predetermined peripheral speed. The pipe P is bent along the outer peripheral surface of the bending die 12, and the bending radius R of the bending portion of the pipe P is determined by the distance from the rotation center line of the bending die 12 to the outer peripheral surface and the cross-sectional radius of the pipe P. Determined by the sum of

  The clamp 16 includes a clamper 14 that can pivot about the rotation center line of the bending mold 12 and that can advance and retract toward the rotation center line of the bending mold 12. The clamp 16 advances the clamper 14 at a position where the pipe P and the bending die 12 first contact each other (the position of the origin of the reference coordinate system, hereinafter referred to as “bending start position”) O. P is pressed against the bending die 12 (clamped to the bending die 12). When the bending mold 12 is turned by the turning angle θm from the bending start position O in accordance with the rotation of the bending mold 12 in the clamped state, the clamper 14 is moved backward to release the pressing of the pipe P to the bending mold 12 (bending mold). Unclamp from 12). By the operation in cooperation with the bending mold 12, a bending portion B having a bending radius R and a bending angle θm is formed.

  In addition, the turning angle of the clamp 16 can be changed, thereby forming a bent portion having a desired bending angle.

  The rotary chuck 18 rotates the pipe P around the center line of the pipe P. The rotating chuck 18 holds a portion of the pipe P before contacting the bending mold 12 when the bending process is not performed (that is, when the clamp 16 is in an unclamped state), and the pipe P is set in a desired manner. It is configured to rotate at an angle.

  The transport mechanism 22 transports the pipe P at a transport speed that matches the circumferential speed of the bending mold 12 so that the pipe P is in the direction 20, strictly speaking, the center line of the pipe P matches the Xa axis of the reference coordinate system. It is configured as follows.

  The holding roller 24 is used to maintain the contact between the bending die 12 and the pipe P during the bending process. Specifically, the pressing roller 24 is pressed against the bending mold 12 by the clamper 14 of the clamper 16 during the bending process. This is to prevent parts other than the part of the pipe P from being separated from the bending mold 12.

  According to such a pipe bender 10, the pipe P sent from the transport mechanism 22 is clamped to the bending mold 12 by the clamp 16 at a certain distance from the tip of the pipe P, and a bent portion having a desired bending angle is obtained. The pipe P is formed into a bending pipe having a desired shape by being rotated by the rotary chuck 18 just before a bent portion is formed.

  Next, bending conditions given to the pipe bender 10 will be described.

  FIG. 2 shows the bending pipe P1 processed according to the bending processing condition table of FIG. 3 and the pipe P1 'before being processed into the bending pipe P. The bending pipe P1 and the pipe P1 'show only the center line. Here, in order to simplify the explanation, it is assumed that no springback occurs.

  According to the bending process condition table shown in FIG. 3, first, the first bent portion B1 is formed at a bending angle θ1 with a point at a distance F1 from the tip of the pipe P1 ′ as a bent portion tip. The distance F1 is also referred to as a feed amount since it is also the amount that the tip of the pipe P1 'is sent from the bending start position O to the tip of the pipe P1'.

  Next, a bending portion B2 having a bending angle θ2 is formed with a point where the pipe P1 'is fed at a feeding amount F2 following the feeding amount F1 (a point F1 + F2 from the tip) as a bending portion tip point. Before the formation of the bent portion B2 is started, that is, before the pipe P1 ′ is clamped to the bending mold 12 by the clamp 16, the rotary chuck 18 rotates the center line of the pipe P1 ′ by an angle φ2. The

  Finally, a bent portion B3 having a bending angle θ3 is formed with a point (F1 + F2 + F3 from the tip) where the pipe P1 'is further fed by the feed amount F3 as a bent portion tip point. Before the formation of the bent portion B3 is started, the rotary chuck 18 rotates the pipe P1 'around the center line of the pipe P1' by an angle φ3.

  As shown in FIGS. 2 and 3, the bending radii of the three bent portions B1 to B3 are common to R1. That is, the bending portions B1 to B3 of the bending pipe P1 are formed by one bending mold.

  The bending pipe P1 is formed through the process according to the bending condition table shown in FIG.

  From here, the system which calculates the bending process condition of the suitable pipe provided to a pipe vendor in order to obtain the bending pipe of the target shape which is this invention is demonstrated.

  The system according to the present invention is a countermeasure against springback that must be taken into account during pipe bending, and calculates bending conditions necessary to obtain a bending pipe with a target shape while taking into account the effects of springback. belongs to.

  Therefore, the system according to the embodiment of the present invention is configured around a computer 100 as shown in FIG. 4, and the computer 100 is configured to bend a central processing unit 102 and a keyboard and a storage medium (not shown). An input device 104 for inputting information necessary for calculating the machining conditions from the user, an output device 106 for outputting the calculated bending conditions to the user, and necessary for calculating the bending conditions. And a storage device 108 for storing programs and tables.

  The central processing unit 102 is configured to control the input device 104 and the output device 106 and to be able to access the storage device 108. Specifically, the information input via the input device 104 and the storage device 108 are configured. The bending processing conditions are calculated using the program and data stored in, and the calculated bending processing conditions are output to the output device 106.

  The input device 104 is for taking in information on the bending pipe of the target shape from the user to the computer 100. Specifically, the input device 104 is for obtaining information on the pipe that is the material of the bending pipe and information on the target shape from the user. It is. For example, when the input device 104 is a keyboard and the output device 106 is a display, the pipe information table shown in FIG. The numerical values of the total length L, the outer diameter d1, the inner diameter d2, the Young's modulus E, the yield stress σy, and the hardening coefficient Eh are inputted with the keyboard, and the pipe information is taken into the computer 100.

  Further, the target shape information is expressed by a table similar to the bending process condition table shown in FIG. 3. For example, the target shape information table shown in FIG. 6 stored in the storage device 108 is displayed on the display as will be described later. The feed amounts F1 to Fn, the rotation angles φ1 to φn, the bending radii R, the bending angles indicating the positions on the pipes where the respective bending portions are formed, regarding the plurality of bending portions 1 to n included in the bending pipe of the target shape. Numerical values of θ1 to θn are taken into the computer 100 through keyboard input by the user.

  The output device 106 is a display, a printer, or the like, and is configured to output information on bending conditions necessary for obtaining a bending pipe having a target shape, or to output the bending pipe having a target shape as an image. ing.

  As shown in FIG. 7, the storage device 108 is a program for causing the computer 100 to calculate the bending process conditions, and as another program, for example, the thickness of the bending pipe processed by using the calculated bending process conditions. A program for analyzing the distribution is stored.

  In addition, various tables are stored in the storage device 108. In addition to the pipe information table and the target shape table described above, a bending condition table as shown in FIG. 8 similar to the table in FIG. A possible bending radius table as shown in FIG. 9 showing the types of bending dies that can be used by the pipe bender and the bending radius data is stored.

  Next, an example of the bending condition calculation operation executed by the pipe bending condition calculation system, that is, executed by the computer 100 driven by the bending condition calculation program will be described with reference to a flow.

  FIG. 10 shows an example of the flow of the bending operation calculation operation.

  First, in step S200, information on a pipe that is a material of a bending pipe is acquired by an input via the input device 104 of the user's computer 100. Thereby, a pipe information table as shown in FIG. 5 is acquired.

  Next, in step S210, a target shape information table is acquired by an input via the input device 104 of the user's computer 100. Thereby, for example, a target shape information table as shown in FIG. 6 for forming the bending pipe Pg shown in FIG. 11 is acquired.

  In subsequent step S220, the center line of the bending pipe of the target shape (hereinafter referred to as “target center line”) is calculated from the target shape information table acquired in step S210, and each of a plurality of points constituting the target center line is calculated. The coordinates of are calculated. For example, as shown in FIG. 12, the coordinates of each of a plurality of points constituting the target center line CLg in the reference coordinate system described above are calculated.

  In addition, simply supplementing, the coordinates in the reference coordinate system of each of the plurality of points constituting the center line of the pipe can be calculated based on the following idea.

  That is, the coordinates of each of the plurality of points constituting the center line of the pipe change each time one of feeding by the transport mechanism, bending by the bending mold, and rotation of the rotary chuck is performed.

  An example of an idea for obtaining the coordinates of the center line in such a case will be described. First, as shown in FIG. 13, when the pipe P is fed by Δxa in the Xa axis direction by the transport mechanism 22, the point Cn on the center line CL moves to the coordinates of the reference coordinate system in which the Xa coordinate component is incremented by Δxa. To do. Coordinate conversion is performed so that Cn becomes Cn '. Hereinafter, this coordinate transformation is referred to as “feed coordinate transformation”.

  Further, as shown in FIG. 14, when the pipe P is rotated by an angle Δφ by the rotary chuck 18, the point Cn on the center line CL does not change the value of the Xa coordinate and is on a plane parallel to the Ya-Za plane. It is rotated by an angle Δφ around the Xa axis. Coordinate conversion is performed so that Cn becomes Cn '. Hereinafter, this coordinate transformation is referred to as “rotational coordinate transformation”.

  Further, as shown in FIG. 15, when a bending portion B having a bending radius R with a bending angle Δθ is formed by the bending mold 12, the point Cn on the center line CL does not change the value of the Za coordinate, and Xa− On the Ya plane, it is rotationally moved by Δθ around the rotation center line of the bending mold 12. Coordinate conversion is performed so that Cn becomes Cn '. Hereinafter, this coordinate transformation is referred to as “bending coordinate transformation”.

  Therefore, each time the feed by the transport mechanism, the bending process by the bending mold, or the rotation of the rotary chuck is performed, the corresponding feed coordinate conversion, rotational coordinate conversion, or bending coordinate conversion constitutes the center line CL. Executed on a point. Thereby, the coordinate in the reference coordinate system of each of the plurality of points constituting the center line CL having a complicated shape can be calculated.

  Returning to FIG. 10, in step S230, the shape of the target center line CLg is output to the output device 106 as an image (an image as shown in FIG. 12). Alternatively or in addition, the central processing unit 102 outputs an image of the bending pipe of the target shape (an image as shown in FIG. 11) based on the pipe information table acquired in step S200 and the shape of the target center line CLg. May be.

  Next, in step S240, as shown in FIG. 16, a plurality of comparison points C0 to Ce are defined from the points constituting the target center line CLg. The comparison point C0 is the tip point of the target center line CLg (so-called pipe tip), the comparison point Ce is the rear end point of the target center line CLg, and the remaining comparison points are the bend tip point, the bend point midpoint, This is the rear end point of the bent part.

  When the definition of the comparison points is completed in step S240, an image of the target center line CLg (an image as shown in FIG. 16) with a plurality of comparison points C0 to Ce is output to the output device 106 in the subsequent step S250.

  Next, an allowable shape difference (allowable error) between the bending pipe having the shape calculated by the system (computer 100) (details will be described later) and the bending pipe having the target shape is input from the user in step S260. Know via device 106. Specifically, an allowable distance between the comparison point of the bending pipe having the target shape and the corresponding comparison point of the bending pipe having the shape calculated by the system (computer 100) by an input through the input device 106 of the user. Get the value of.

  In step S270, a bending condition table is created. Here, a bending condition table as shown in FIG. 8 is created in which each parameter on the table is the same as the parameter of the target shape information table obtained in step S210.

  In step S280, the influence of springback generated in each bent portion when the pipe is bent using the bending condition table created in step S270 (or corrected in step 360 described later) is calculated. Specifically, for each of the plurality of bending portions B1 to Bn shown in the bending process condition table, referring to the pipe information table acquired in step S200, and using the bending radius R and the bending angle θ shown in the bending process table, The bending angle θ ′ after the spring back is calculated.

  For example, the bending part B1 will be described. When the bending portion B1 having the bending radius R1 and the bending angle θ1 is formed, the bending radius R1 ′ after the springback can be obtained from the equation shown in Equation 1.

  In the equation shown in Equation 1, d1, d2, σy, E, and Eh are an outer diameter, an inner diameter, a yield stress, a Young's modulus, and a hardening coefficient provided from the pipe information table.

  When the bending radius R1 'after the occurrence of the springback is obtained, the bending angle θ1' after the occurrence of the springback can be obtained from the equation shown in Equation 2.

  In step 290, the bending angle ratio α is calculated. The bending angle ratio α is a value obtained by dividing the bending angle θ of the bending condition table by θ ′ after springback and is a value of 1 or more. A bending angle ratio α is calculated for each of the bent portions B1 to Bn.

When the bending angle ratio α of each of the bent portions B1 to Bn is obtained in step S290, the bending angle θ of the bending processing condition table is corrected and changed to the bending angle θa obtained by adding the bending angle ratio α to the bending angle θ in step S300. To do. FIG. 17 shows a bending condition corrected bending process condition table.

  Subsequently, in step S310, as calculated from the target shape table in step S220, the center line of the pipe processed under the bending conditions of the bending condition corrected bending condition table while taking into account the influence of the springback. The shape of is calculated. Hereinafter, the calculated pipe center line is referred to as a “corrected center line” because it can be considered that the target center line is corrected in consideration of the influence of springback.

  Further, in step S320, a plurality of comparison points are defined on the correction center line as well as a plurality of comparison points on the target center line in step S240. The position and number of comparison points defined on the correction center line are the same as the position and number of comparison points defined on the target center line.

In step S330, the positional relationship between each of the plurality of comparison points on the target center line and the corresponding comparison point on the corrected center line is determined. In the determination, it is determined whether or not the distance between each comparison point on the target center line and the corresponding comparison point on the correction center line exceeds the allowable error acquired in step S260. To explain in an easy-to-understand manner, when the correction center line CLa and the target center line CLg are arranged in the reference coordinate system as shown in FIG. 18, the distance due to the influence of the springback between the respective rear end points C0 and C0 ′. Can be seen. As in C0 and C0 ′, it is determined whether or not the distance between the corresponding comparison points exceeds the allowable error.

  In step S340, as a result of the determination in step S330, when there is at least one pair whose distance between the comparison points of the target center line and the comparison center line of the correction center line corresponding to the distance between them exceeds the allowable error, Proceed to step S350. Otherwise, the process proceeds to step S370.

  In step S350, referring to the possible bending radius table shown in FIG. 9 stored in the storage device 108, a different bending radius R usable by the pipe bender is selected. For example, a bending radius R having the next smallest radius is selected, or a plurality of bending radii R are ordered in advance in the possible bending radius table, and are selected according to the order.

  Next, in step S360, the bending radius of the bending condition table created in step 270 is changed and corrected to the different bending radius selected in the previous step S350. For example, FIG. 19 illustrates a bending radius corrected bending processing condition table that is changed and corrected to the bending radius R2. Then, the process returns to step S280.

  In step S370, the bending condition table when it is determined NO in step S330 is output to the user via the output device 106 as a bending condition table necessary for obtaining a bending pipe having a target shape.

  When the calculated bending condition is output in step 370, the bending condition calculation flow is completed.

  According to this embodiment, when comparing the calculated shape obtained by calculating the shape of the pipe that is sequentially bent while taking into account the effect of springback for each bent portion, the target shape and the vicinity of the previously formed bent portion. Considering that the distance between the corresponding comparison points appears as an influence on the distance between the corresponding comparison points in the vicinity of the next formed bent part, the distance between the corresponding comparison points is allowable. The machining conditions corrected to be within the error are calculated. In addition, the overall shape of the pipe machined according to the calculated bending process conditions does not deviate greatly from the target shape. Furthermore, since the influence of the springback in each bent portion is calculated by, for example, material mechanical calculation with respect to the center line, the calculation time is shortened as compared with the case where the finite element method is used.

  While the present invention has been described with reference to one embodiment, the present invention is not limited to this.

  For example, the bending thickness of the bending pipe as shown in FIG. 20 and the equivalent strain distribution as shown in FIG. 21 may be calculated and output from the calculated bending conditions using the finite element method. In the bending pipe Px of FIG. 20 and the bending pipe Py of FIG. 21, the thickness and strain distribution are expressed as contour lines. In that case, it is necessary to store a plate thickness distribution analysis program or an equivalent strain distribution analysis program in a storage device of the computer.

  This is because, when a bending pipe manufactured under the bending conditions calculated according to the present invention is hydroformed, information on the plate thickness distribution and the equivalent strain distribution is useful for hydroforming.

  Further, the bending condition calculation method of the present invention is not greatly influenced by the cross-sectional shape of the pipe. In the above-described embodiment, the cross-sectional shape of the pipe is circular, but the present invention can also be applied to a pipe Pz having a square cross-sectional shape as shown in FIG. This is because the present invention calculates the bending process condition based on the center line of the pipe as described above.

  In the above-described embodiment, the pipe bender and the pipe bending process condition calculation system are separate, but may be integrated. For example, when a user inputs a target shape to a pipe vendor, a control unit in the pipe vendor calculates a bending process condition necessary for obtaining a bending pipe having a target shape (that is, the control unit performs the above-described embodiment). It is possible to realize a pipe vendor in which the pipe bending mechanism bends the pipe based on the calculated bending conditions.

  In the above-described embodiment, the bending radius of the bending pipe is the same, but it is obvious to those skilled in the art that bending conditions for the bending pipe that can be different for each bending portion can be calculated. However, the time required to finish calculating the bending process conditions is proportional to the number of bent portions.

  The present invention can provide the bending conditions necessary for obtaining a bending pipe having a target shape to any apparatus related to the bending process of the pipe.

It is a figure which shows the structure of a pipe vendor roughly. It is a figure for demonstrating bending process conditions. It is a figure which shows the bending process condition table relevant to FIG. It is a figure which shows the structure of the pipe bending process condition calculation system which concerns on one Embodiment of this invention. It is a figure which shows the pipe information table memorize | stored in the memory | storage device. It is a figure which shows the target shape information table memorize | stored in the memory | storage device. It is a figure which shows the structure of a memory | storage device. It is a figure which shows the bending process condition table memorize | stored in the memory | storage device. It is a figure which shows the possible bending radius table memorize | stored in the memory | storage device. It is a figure which shows the flow of calculation operation | movement of the pipe bending process conditions of a system. It is a figure which shows the bending pipe of a target shape. It is a figure which shows a target centerline. It is a figure explaining how to obtain | require the coordinate of the point on a target centerline. It is a figure explaining how to obtain the coordinates of points on different target center lines. It is a figure explaining how to obtain the coordinates of a point on a different target center line. It is a figure which shows the target centerline which attached | subjected the several comparison point. It is a figure which shows the bending process condition table by which the bending angle was correct | amended. It is the figure which has arrange | positioned the target centerline and the correction | amendment centerline in the reference coordinate system. It is a figure which shows the bending process condition table by which the bending radius was correct | amended. It is a figure which shows the board thickness distribution of a bending pipe. It is a figure which shows the equivalent strain distribution of a bending pipe. It is a figure which shows the pipe of the cross-sectional shape which can calculate the bending process conditions by this invention.

Claims (4)

A pipe bending condition calculation system for calculating bending conditions provided to a pipe vendor that performs bending at a plurality of locations of a pipe,
Target shape information acquisition means for obtaining target shape information of a pipe including information on a bending radius and a bending angle of a bent portion;
A comparison point defining means for defining a plurality of comparison points on the center line of the pipe;
Based on the target shape information, processing condition calculation means for calculating bending conditions including a bending radius and a bending angle while taking into account the effect of springback for each bending portion of the pipe;
Processing shape calculation means for calculating the shape of the pipe that is sequentially bent based on the bending processing conditions calculated by the processing condition calculation means for each bending portion;
A positional relationship determining means for determining a positional relationship between a comparison point of a pipe having a target shape and a corresponding comparison point of the calculated shape pipe calculated by the machining shape calculation stage;
The processing condition calculation means uses only the outer diameter d1, the inner diameter d2, the yield stress σy, the Young's modulus E, and the hardening coefficient Eh of the pipe as parameters when calculating the bending processing conditions while taking into account the effect of springback. When the bending angle θ included in the target shape information is corrected based on the following equations 1, 2, and 3, and the determination result of the positional relationship determination means deviates from a predetermined allowable range A pipe bending condition calculation system that calculates a corrected bending condition by correcting the bending radius R included in the target shape information so that the determination result falls within the allowable range.

Here, R ′ and θ ′ are the bending radius and bending angle of the pipe after springback calculated by the processing condition calculation means, and θa is also considered by the influence of the springback calculated by the processing condition calculation means. It is the bending angle of the pipe as the bending process condition corrected by the above. In the pipe bending processing condition calculation system according to claim 1,
When determining the positional relationship between the comparison point of the corresponding target shape pipe and the comparison point of the calculated shape pipe, the positional relationship determination means determines whether the distance between the comparison points exceeds a predetermined allowable range. A pipe bending condition calculation system characterized by determining whether or not . A pipe bending condition calculation program for driving a computer to calculate bending conditions to be provided to a pipe vendor that performs bending at a plurality of locations on a pipe,
Computer
Target shape information acquisition means for obtaining target shape information of a pipe including information of a bending radius and a bending angle of a bent portion;
A comparison point defining means for defining a plurality of comparison points on the center line of the pipe;
Based on the target shape information, a processing condition calculation means for calculating a bending processing condition including a bending radius and a bending angle while taking into account the effect of springback for each bending portion of the pipe,
Machining shape calculation means for calculating the shape of a pipe that is sequentially bent based on the bending conditions calculated by the machining condition calculation means for each bending portion; and
Function as positional relationship determination means for determining a positional relationship between a comparison point of a pipe having a target shape and a corresponding comparison point of a pipe having a calculated shape calculated by the machining shape calculation stage; and
When functioning as the processing condition calculating means, when calculating bending conditions while taking into account the effect of springback, the outer diameter d1, inner diameter d2, yield stress σy, Young's modulus E, and hardening coefficient Eh of the pipe are used as parameters. The bend angle θ included in the target shape information is corrected based on the following equations 1, 2, and 3, and the determination result of the positional relationship determination means deviates from a predetermined allowable range. If so, a pipe bending condition calculation is made to function so as to calculate a corrected bending condition in which the bending radius R included in the target shape information is corrected so that the determination result falls within the allowable range. program.

Here, R ′ and θ ′ are the bending radius and bending angle of the pipe after springback calculated by the processing condition calculation means, and θa is also considered by the influence of the springback calculated by the processing condition calculation means. It is the bending angle of the pipe as the bending process condition corrected by the above. A pipe bender that includes a pipe bending device for bending a pipe and performs bending at a plurality of locations on the pipe based on predetermined bending conditions,
Target shape information acquisition means for obtaining target shape information of a pipe including information on a bending radius and a bending angle of a bent portion;
A comparison point defining means for defining a plurality of comparison points on the center line of the pipe;
Based on the target shape information, processing condition calculation means for calculating bending conditions including a bending radius and a bending angle while taking into account the effect of springback for each bending portion of the pipe;
Processing shape calculation means for calculating the shape of the pipe that is sequentially bent based on the bending processing conditions calculated by the processing condition calculation means for each bending portion;
A positional relationship determining means for determining a positional relationship between a comparison point of a pipe having a target shape and a corresponding comparison point of the calculated shape pipe calculated by the machining shape calculation stage;
The processing condition calculation means uses only the outer diameter d1, the inner diameter d2, the yield stress σy, the Young's modulus E, and the hardening coefficient Eh of the pipe as parameters when calculating the bending processing conditions while taking into account the effect of springback. When the bending angle θ included in the target shape information is corrected based on the following equations 1, 2, and 3, and the determination result of the positional relationship determination means deviates from a predetermined allowable range , Calculating a corrected bending process condition in which the bending radius R included in the target shape information is corrected so that the determination result falls within the allowable range;
The pipe bending apparatus, wherein the pipe bending apparatus performs bending on a pipe based on either the bending condition or the corrected bending condition.

Here, R ′ and θ ′ are the bending radius and bending angle of the pipe after springback calculated by the processing condition calculation means, and θa is also considered by the influence of the springback calculated by the processing condition calculation means. It is the bending angle of the pipe as the bending process condition corrected by the above.

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