JP2005271004A - Interference avoiding apparatus and method for robot welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interference avoiding apparatus for robot welding and an apparatus therefor by which automatic welding sequence can be made up to avoid the interference. <P>SOLUTION: The interference avoiding apparatus for robot welding, which avoids the interference between a torch and a workpiece in forming a cruciform joint by performing fillet welding on the intersection of a web material, is provided with: a torch section that can move in a welding direction while holding a downward posture for the purpose of performing fillet welding; a fixture for fixing the web material; an input section for inputting workpiece dimensional data of the fixed web material; an arithmetic section for detecting presence/absence of a required width from the torch to the end of a flange material; a discrimination section that, in the case of possibility of interference, calculates and instructs a rotational amount for the purpose of securing suitable space between the torch and the flange material with respect to a motor; and the motor that performs positioning of the web material by rotating the fixture, upon receiving the instruction of the discrimination section, in a vertical plane around the intersection of the two web materials. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a robot welding interference avoidance apparatus and method capable of avoiding interference between a torch part and a workpiece and efficiently performing welding with a high welding current.

  In order to perform fillet welding at the intersection of two web materials in a cross column with an SRC structure used for building steel frames, a welding torch or torch is held in the gap between the flange materials fixed to the two web materials It is necessary to insert a member (hereinafter simply referred to as a torch portion) to be welded.

  When welding by inserting the torch part between workpieces, considering the deformation of the member due to welding heat etc., the torch part is inserted at a position where a gap including an interval including a presumed thermal strain amount can be secured. It is important to do. In addition, in the fillet welding of a cruciform column, positioning is performed in such a way that a high welding current can be used to ensure high efficiency, i.e., the intersection of two web materials is oriented in the vertical direction of the torch as much as possible, and two flanges are used. It is preferable that welding is performed in a state in which the torch portion is in a substantially downward posture with respect to the space formed by.

  For example, as shown in FIGS. 6 (a) and 6 (b), the cross column is often an asymmetric type other than the two web members 11 arranged symmetrically. Usually, in the fillet welding of such an asymmetrically arranged column, the apparent straight line connecting the torch portion 1 and the point where the two web members 11 intersect each other is positioned so as to face the center of the earth. , Welding is performed by allowing the torch portion 1 to enter the space between the two flange members 12 in a substantially downward direction. At this time, even when the torch part 1 interferes with the flange member 12 or does not interfere, interference may occur due to deformation due to welding heat.

  Conventionally, the positional relationship between the torch part and the workpiece is illustrated with respect to such interference, and this is confirmed visually, and the posture of the torch part is changed, or the positional relationship and interference in which the interference between the torch part and the workpiece is assumed. A method for avoiding interference between the torch part and the workpiece by performing an intrusion check in the interference space of the torch part using a predetermined interference check simulator as a space and moving the torch part has been adopted. However, this method has a problem that it is not possible to ensure the appropriateness of the bead shape in which the torch posture is likely to be a dominant factor.

  Therefore, in order to avoid the interference between the torch part and the workpiece, for example, the reading part 101 for changing the torch angle and the like, the torch angle changing part 102, the interference checking part 103, and the torch angle extracting part 104 that does not interfere are configured. A robot welding interference avoidance device (Patent Document 1, Paragraph 0023, FIG. 1) having a posture change control system main body 100 and a posture change control data unit 200 that stores posture change control data read by the reading unit 101 is proposed. Has been. In addition, the operator operates the teaching operation panel to specify the shape type of the robot motion allowable region (Step 1), the step of inputting the parameter Ci that specifies the dimension of the specified shape (Step 2), the robot A function ± f (Xs, for the step of calculating the function fi for expressing the motion allowable region (Step 3), the step of obtaining the reference point belonging to the cage (Step 4), and the reference point S (Xs, Ys, Zs) Ys, Zs) A software cage function having a step (Step 5) and a step (Step 6) of selecting a function value having a positive value and setting it as a function representing a robot motion allowable boundary surface (Step 6) A robot control method provided (Patent Document 2, paragraphs 0024 to 0027, FIG. 3) has been proposed.

  However, the technique of Patent Document 1 determines the torch posture based on the angle range registered in the database, the angle change step pitch, etc., performs the interference check in that posture, and repeats the angle change until there is no interference. Although it is possible to avoid interference within the limited range, it is difficult to automate the repetition of a series of operations, especially in a column with at least two joints with similar characteristics such as a cross column, two or more joints There is a problem that it is inefficient because it is not possible to set up a procedure for automatically welding the materials one after another. Further, the technique of Patent Document 2 has a similar problem.

JP 2001-328092 A Japanese Patent Application Laid-Open No. 07-129214

  The present invention has been made in view of such problems, and it is easy to assemble a sequence for automatically welding two or more joints sequentially while avoiding interference between the torch part and the workpiece. It is an object of the present invention to provide a robot welding interference avoidance device and method that can automate the operation and increase the welding efficiency by securing an appropriate welding posture.

  The robot welding interference avoidance device according to the first aspect of the present invention is a robot welding interference that avoids interference between a torch part and a workpiece when crossing two web members and performing fillet welding on the intersecting portion to form a cross pillar. In the avoidance device, in order to perform the fillet welding, a torch portion that can maintain a downward posture and move in the welding line direction, a fixing device that fixes the two web members forming the cross column, and a fixing device fixed to the fixing device. A data input device for inputting workpiece dimension data of a web material, and a size of a space formed between the flange materials at the end of the web material fixed to the fixture based on the input data, and the torch unit When there is a possibility that the arithmetic device for detecting the presence or absence of the necessary width from the flange member to the flange member and the torch part and the flange member may interfere with each other, the drive device connected to the fixture is A determination device that calculates and indicates a rotation amount for securing an appropriate space between the flange portion and the flange material, and receives the instruction from the determination device, and the fixing device is centered on the intersection of the two web materials. And the driving device for positioning the web material by rotating in a vertical plane.

  In the robot welding interference avoidance device according to the present invention, the flange material end position of the web material fixed to the fixture rotated according to the instruction of the determination device is detected, and interference occurs between the torch portion and the flange material end portion. It is preferable to further include a confirmation device for confirming that no occurrence occurs. Moreover, it is preferable to provide a correction device that corrects a dimensional error in an actual workpiece with respect to data input to the data input device. Furthermore, a display device that exemplifies the posture of attaching the web material to the fixture can be provided in advance.

  The robot welding interference avoidance method according to the second aspect of the present invention is a robot welding interference that avoids interference between a torch part and a workpiece when crossing two web materials and forming a cross column by applying fillet welding to the intersecting portion. In the avoidance method, the step of fixing the two web members forming the cross pillar to the fixture, the step of inputting the workpiece dimension data of the fixed web material to the data input device, and the fixture based on the input data A step of calculating a size of a space formed between the flange members of the fixed web material end portion and detecting the presence or absence of a necessary width from the torch portion to the end portion of the flange material; and the torch portion and the flange When there is a possibility of interference with the material, the fixing device is rotated in a vertical plane around the intersection of the two web materials to secure an appropriate space between the torch part and the flange material. And that step, characterized in that a step of applying a fillet weld at the intersection of the web material said torch portion while maintaining a flat position by entering the appropriate space.

  In this robot welding interference avoidance method, it is confirmed that there is no interference between the torch portion and the flange material end after the step of rotating the fixing tool to secure an appropriate space between the torch portion and the flange material. Preferably, the method further includes the step of:

  The method preferably further includes a correction step of correcting a dimensional error in the actual workpiece with respect to the workpiece dimension data or the like input in the input step. Furthermore, the display process which illustrates previously the attitude | position which fixes a web material to the said fixing tool can be further included.

  According to the robot welding interference avoidance device according to the first invention of the present application, not only can the apparatus be prevented from being damaged by avoiding interference between the torch part and the workpiece, but also an appropriate space where interference can be avoided is uniquely determined. It becomes easy to form a sequence for automatically welding two or more joints sequentially, and a series of operations can be automated. In addition, it is possible to efficiently form a cross pillar with a high welding current while ensuring an appropriate welding posture. In this apparatus, the interference can be more reliably avoided by further providing a confirmation device for confirming that no interference occurs between the flange material end after positioning and the torch part. Further, by providing a correction device that corrects a dimensional error in an actual workpiece, the error can be corrected and interference can be avoided more reliably. Furthermore, by providing a display device that exemplifies the posture of attaching the web material to the fixture in advance, the operator can more accurately fix the web material.

  According to the robot welding interference avoidance method according to the second invention of the present application, an appropriate space in which interference between the torch part and the workpiece can be avoided is uniquely determined. Therefore, a series of operations are automated to ensure an appropriate welding posture. In addition, a cross column can be efficiently formed with a high welding current. In this method, by further providing a confirmation step for confirming that no interference occurs between the flange member end after positioning and the torch part, the interference between the torch part and the workpiece can be avoided more reliably. Further, by providing a correction process for correcting the dimensional error in the actual workpiece with respect to the data input in the data input process, it is possible to correct the dimensional error of the input data and avoid interference more reliably. Furthermore, the work efficiency can be improved by further providing a display step that illustrates in advance the posture of attaching the web material to the fixture.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a front view showing a robot welding interference avoidance apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line 2-2 in FIG. 1, and FIG. 3 is a robot according to an embodiment of the present invention. It is a block diagram which shows the partial structure of a welding interference avoidance apparatus.

  In FIG. 1, two web members 11 are fixed along a length direction of a horizontally long fixing tool 2 having a horizontal axis that is installed on a support base 3 that supports both ends. The fixing tool 2 is a cylindrical member arranged horizontally, and has slits (not shown) for inserting and fixing the web material 11 in the vicinity of both ends thereof. The web members 11 cross each other at a predetermined angle, and a weld line 9 is formed along the length direction thereof. A torch portion 1 is disposed above the fixture 2. The tip of the welding rod of the torch part 1 is located at the intersection of the two web members 11 and is movable along the weld line 9 along the length direction. The flange material 12 is fixed to the open end of the web material 11 on the non-crossing side along the length direction, and the interval between the adjacent flange materials 12 is narrower than the interval between the adjacent web materials 11. It has become. A motor 6 as a driving device is connected to the horizontal axis of the fixture 2.

  The apparatus of this embodiment has a display device (not shown). The display means has a display screen, and the posture of fixing the web material 11 to the fixture 2 is exemplified in advance on this screen. Therefore, the operator can fix the web material 11 to the fixture 2 according to the sample of the display device. Moreover, this apparatus has the input part 4 as a data input device, as shown in FIG. 3, and the input part 4 has a data recording part. Work size data, calculation parameters, and the like of the web material 11 fixed to the fixture 2 are input to the input unit 4 by an operator. In addition, a dimensional error correction unit 10 as a correction device is provided adjacent to the input unit 4. The dimension error correction unit 10 includes a measurement unit, a calculation function unit, and a data recording unit, and corrects an error such as a data size input to the input unit 4 based on an actual measurement dimension of an actual workpiece.

  In addition, this device has a calculation unit 5 as a calculation device, and the calculation unit 5 has a calculation function unit, which is based on data input to the input unit 4 and data corrected by the correction device. The size of the space formed between the flange members 12 at the ends of the web member 11 fixed to the fixture 2 is calculated, and the presence or absence of the necessary width from the torch portion 1 to the end of the flange member 12 is detected. Furthermore, this apparatus has a determination unit 7 as a determination apparatus. The determination unit 7 includes a calculation function unit and a comparison determination unit. When there is a possibility that the torch unit 1 and the flange material 12 interfere with each other, an appropriate space is secured between the torch unit 1 and the flange material 12. The motor 6 as a driving device is instructed for the amount of rotation to be performed. In response to an instruction from the determination unit 7, the motor 6 rotates the fixture 2 in the vertical plane around the horizontal axis that is the intersection of the two web materials 11 to position the web material 11. The calculation unit 5 and the determination unit 7 are collectively referred to as a workpiece positioning angle determination unit 8.

  Next, the operation of the apparatus configured as described above and the robot welding interference avoidance method will be described. Prior to the welding operation, the operator performs the two web members 11 according to a display device that exemplifies the mounting posture of two web members 11 (hereinafter, also referred to as a cross column for convenience) for forming the cross pillars. Is fixed to the fixture 2. Next, workpiece dimension data, calculation parameters, and the like of the web material 11 are input to the input unit 4. When a workpiece dimension or the like is input to the input unit 4, the calculation unit 5 calculates the size of the space between the flange 12 end portions of the two web members 11 based on the input data, and the torch unit 1. To the end of the flange member 12 is detected. As a result, when there is a possibility that the torch part 1 and the cross pillar interfere with each other, the determination part 7 calculates the rotation amount of the fixture 2 necessary for avoiding the interference. The calculated rotation amount signal is sent to a motor 6 as a driving device. The motor 6 that has received the signal from the determination unit 7 rotates the fixture 2 by a necessary amount around the horizontal axis that is the intersection of the two web members 11, and is necessary for the torch unit 1 to enter the welding position. A space portion is formed. After the necessary space portion is formed, the torch portion 1 enters the welding position through the space portion between the end portions of the flange member 12, and fillet welds are performed along the weld line 9 to form a cross pillar.

  Next, the work positioning angle determination method will be described in detail with reference to FIGS. When workpiece dimension data or the like is input to the input unit 4 by an operator, interference may occur between the torch unit 1 and the web material 11 and the flange material 12 as the workpiece in the calculation unit 5 and the determination unit 7. If there is a possibility of interference, necessary measures are taken to eliminate this. That is, in the calculation unit 5, the welding position 13 and the flange material 12 </ b> A in FIG. 5 are based on the workpiece dimension data input to the input unit 4 and the data corrected by the dimension error correction unit 10 according to the block diagram of FIG. 4. An angle θf1 between the straight line connecting the end portions and the web material 11A and an angle θf2 between the straight line connecting the welding position 13 and the end portions of the flange material 12B and the web material 11B are obtained. Thereby, the size of the space between the flange members 12A and 12B is determined. Next, the angles θa1 and θa2 corresponding to the opening dimension a are obtained based on the opening dimension a necessary for the entry of the torch portion 1, and the angle α and the angle for avoiding the flange 12A from these θf1, θa1, θf2, and θa2, respectively. An angle β for avoiding the flange 12B is obtained. Thereby, the presence or absence of the necessary width from the torch part 1 to the end parts of the flange members 12A and 12B is detected.

  Next, the determination unit 7 compares the angle α and the angle β obtained by the calculation unit 5 according to the block diagram of FIG. 4, determines whether or not there is a possibility of interference between the torch unit 1 and the lunge unit, When there is a possibility of interference, a necessary instruction is given to the motor 6. That is, when the angle α is equal to or smaller than the angle β, the positioning of the two web members 11A and 11B is performed on the condition that the workpiece positioning angle γ for the downward welding is between the angle α and the angle β. The rotation amount θ in the counterclockwise direction in FIG. 5 for performing is determined as γ, and the signal is sent to the motor 6. Upon receiving the signal, the motor 6 rotates the fixture 2 in accordance with the instruction, and the cross pillar rotates along with this rotation, and a necessary upward space is formed between the flanges 12A and 12B. The torch part 1 enters the space part in an appropriate posture and forms a cross pillar by fillet welding (FIG. 4A).

  Next, the cross is made on condition that the angle α is equal to or smaller than the angle β, the workpiece positioning angle γ for the downward welding is not between the angles α and β, and the angle γ is smaller than the angle α. The counterclockwise rotation amount θ in FIG. 5 for positioning the column is determined to be α (FIG. 4B), the signal is sent to the motor 6, and the cross column is rotated by the rotation of the fixture 2. In the same manner, a cross pillar is formed.

  Next, in order to position the cross column on the condition that the angle α is equal to or smaller than the angle β, γ is not between the angles α and β, and the angle γ is not smaller than the angle α. The rotation amount θ in the counterclockwise direction in FIG. 5 is determined to be β (FIG. 4C), and a signal for that is sent to the motor 6 to form a cross pillar in the same manner.

  When the angle α is larger than the angle β, it is determined that the torch portion 1 cannot enter the welding position 13 and the operation for forming the cross pillar is stopped (FIG. 4D). Normally, the workpiece positioning angle γ, which is downward welding in fillet welding without a groove, is set to 45 degrees.

  According to this embodiment, when there is a possibility of interference between the torch part 1 and the web material 11 forming the cross pillar, the determination part 7 calculates the rotation amount of the fixture 2 necessary for avoiding the interference and issues an instruction. Then, the motor 6 that has received the instruction rotates the fixture 2 by a necessary amount around the horizontal axis that is the intersection of the two web members 11, so that the space required for the torch 1 to enter is unique. Formed. Therefore, while avoiding interference between the torch portion 1 and the workpiece, a series of welding operations can be automated to efficiently form a cross pillar. Moreover, since the torch part can be maintained in a state close to a downward posture and efficient welding can be performed with a high welding current, the appropriateness of the beat shape can be ensured.

  In this embodiment, after positioning the web material 11 by rotating the fixing tool 2, the position of the flange material 12 of the web material 11 is detected again, and the confirmation for confirming that there is no interference between the torch part and the flange material It is preferable to provide a process. Thereby, the interference between the torch part and the workpiece can be avoided more reliably. Confirmation that there is no interference is performed by, for example, a confirmation unit including a measurement unit, a calculation function unit, and a comparison determination unit.

  The apparatus and method of the present invention that can form a cross column by sequentially and efficiently welding two or more joints while ensuring a downward posture of the torch part and avoiding interference between the torch part and the workpiece. It is useful as an interference avoidance technique in the field of robot welding, and will attract more and more attention in the future.

It is a front view which shows the robot welding interference avoidance apparatus which is embodiment of this invention. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1. It is a block diagram which shows a partial structure of the robot welding interference avoidance apparatus which is embodiment of this invention. It is a flowchart which shows operation | movement of the robot welding interference avoidance apparatus which is embodiment of this invention. It is a figure which shows the workpiece positioning angle determination method in embodiment of this invention. It is a figure which shows the web material which forms a cross pillar.

Explanation of symbols

1: Torch part 2: Fixing tool 3: Support base 4: Input part 5: Calculation part 6: Motor 7: Determination part 8: Work positioning angle determination part 9: Welding line 11A: Web material 11B: Web material 12A: Flange material 12B: Flange material 13: Welding position

Claims (8)

  In a robot welding interference avoidance device that crosses two web materials and avoids interference between the torch part and the workpiece when forming a cross column by applying fillet welding to the intersecting part, it faces downward to perform the fillet welding A torch portion that can maintain the posture and move in the direction of the welding line, a fixture that fixes the two web members forming the cross column, and a data input device that inputs workpiece dimension data of the web material fixed to the fixture; Calculating the size of the space formed between the flange members at the end of the web material fixed to the fixture based on the input data, and determining whether there is a required width from the torch part to the end of the flange material When there is a possibility of interference between the arithmetic device to be detected and the torch part and the flange material, an appropriate space is ensured between the torch part and the flange material for the drive device connected to the fixture. And a determination device that calculates and indicates the amount of rotation, and receives the instruction from the determination device, and rotates the fixture in a vertical plane around the intersection of the two web materials to position the web material A robot welding interference avoidance device comprising the drive device.   A confirmation device that detects a flange material end portion position of the web material fixed to a rotating fixture rotated based on an instruction of the determination device and confirms that no interference occurs between the torch portion and the flange material end portion. The robot welding interference avoidance device according to claim 1, further comprising:   The robot welding interference avoidance device according to claim 1, further comprising a correction device that corrects a dimensional error in an actual workpiece with respect to data input to the data input device.   The robot welding interference avoidance device according to claim 1, further comprising a display device that exemplifies a posture in which the web material is attached to the fixture.   In the robot welding interference avoiding method for avoiding interference between a torch part and a work when crossing two web materials and forming a cross column by performing fillet welding at the crossing part, the two webs forming the cross column Between the step of fixing the material to the fixture, the step of inputting the workpiece dimension data of the fixed web material to the data input device, and the flange material at the end of the web material fixed to the fixture based on the input data When calculating the size of the space to be formed and detecting the presence or absence of the necessary width from the torch part to the end of the flange material, and when there is a possibility that the torch part and the flange material interfere with each other, Securing a proper space between the torch part and the flange material by rotating the fixture in a vertical plane around the intersection of the two web members; and inserting the torch part into the proper space. Robot welding interference avoidance method characterized by a step of applying a fillet weld at the intersection of the web material while maintaining a flat position Te.   The method further includes a step of confirming that no interference occurs between the torch portion and the flange material end portion after the step of rotating the fixing tool to secure an appropriate space between the torch portion and the flange material. The robot welding interference avoidance method according to claim 5.   The robot welding interference avoidance method according to claim 5, further comprising a correction step of correcting a dimensional error in the actual workpiece with respect to the workpiece dimension data input in the input step.   The robot welding interference avoidance method according to any one of claims 5 to 7, further comprising a display step that exemplifies a posture in which the web member is attached to the fixture.

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