Welding module for welding robot, welding robot, and automatic welding method

Abstract

Disclosed are a welding module for a welding robot, a welding robot, and an automatic welding method. The disclosed welding module for a welding robot comprises: a main frame; an adapter coupled to the main frame; a Z-axis motion frame coupled to the main frame and coupled to be movable in a Z-axis direction; an XY-axis motion frame coupled to the Z-axis motion frame and coupled to be movable in an X-axis direction; and a welding machine mounting frame coupled to the XY-axis motion frame and coupled to be movable in a Y-axis direction, wherein the Z-axis, the X-axis, and the Y-axis are perpendicular to each other.

Description

Welding module for welding robot, welding robot and automatic welding method

[0001] A welding module for a welding robot, a welding robot, and an automatic welding method are disclosed. More specifically, a welding module for a welding robot configured to automatically weld a tube sheet and a tube, a welding robot, and an automatic welding method are disclosed.

[0002] Shell-and-tube heat exchangers are manufactured by inserting multiple tubes into tube sheets and then performing joint welding. Typically, hundreds of joint welds (welding type: fillet welds) are performed on the tubes and tube sheets during the manufacturing of shell-and-tube heat exchangers.

[0003] Welding by hand is performed by performing full-position welding in which the welder rotates 360° while inserting one tube into one tube hole, or performing welding in a position other than the top-down position two or more times with the help of a mechanism that can rotate the tube and tube sheet assembly, or performing rotation welding by attaching a detachable orbital welder to the tube.

[0004] Korean Patent Publication No. 10-2012-0133356 proposes a method for measuring coordinates of tube holes within a tubesheet (tube map) using a camera or other device, but does not provide a detailed description of the working tool. Specifically, Korean Patent Publication No. 10-2012-0133356 does not mention a method for inserting and fixing the working tool within the tube, and, because it uses an orthogonal two-axis robot rather than a multi-joint robot, it does not consider the surface orientation of the tubesheet.

[0005] Korean Patent Publication No. 10-2015-0000734 proposes a method for fixing a welding member in position by inserting a fixing member into a tube adjacent to the tube to be welded rather than the tube to be welded and bringing the fixing member into contact with the tube. However, this method is inefficient because it requires a secondary work step of controlling not only the tube to be welded but also other tubes.

[0006] Korean Patent No. 10-1936363 proposes a method of fixing a welding device in position by inserting a tube chucking part into a tube to be welded and expanding two sides of a collet in the radial direction, but does not disclose a method of effectively finding the center of the tube.

[0007] One embodiment of the present invention provides a welding module for a welding robot configured to automatically weld a tube sheet and a tube.

[0008] Another embodiment of the present invention provides a welding robot including a welding module for the welding robot.

[0009] Another embodiment of the present invention provides an automatic welding method using the welding robot.

[0010] One aspect of the present invention is:

[0011] mainframe;

[0012] An adapter coupled to the above main frame;

[0013] A Z-axis motion frame coupled to the above main frame and capable of moving in the Z-axis direction;

[0014] An XY-axis motion frame coupled to the Z-axis motion frame but movable in the X-axis direction; and

[0015] Includes a welding machine mounting frame coupled to the above XY-axis motion frame and movable in the Y-axis direction,

[0016] The above Z-axis, the X-axis and the Y-axis provide a welding module for a welding robot that are perpendicular to each other.

[0017] The welding module for the above welding robot can be configured such that the welding machine mounting frame can move in the Z-axis, X-axis, and Y-axis directions with respect to the main frame.

[0018] The welding module for the above welding robot may further include a pair of main LM rails installed on the bottom surface of the main frame.

[0019] The welding module for the above welding robot further includes a pair of main LM guides installed on the upper surface of the Z-axis motion frame, and the pair of main LM guides are each coupled to the corresponding main LM rails and can be slidably coupled in the Z-axis direction.

[0020] The welding module for the above welding robot may further include a main drive cylinder configured to move the pair of main LM guides in the Z-axis direction.

[0021] The welding module for the above welding robot further includes a first centering block and a first guide cylinder installed on the lower surface of the Z-axis motion frame, the first centering block including a first pivot formed on the central front, and the first guide cylinder may be configured to be coupled with the first centering block to move the first centering block in the Z-axis direction.

[0022] The welding module for the above welding robot may further include a first cam guide installed on the upper surface of the XY-axis motion frame.

[0023] The welding module for the robot may be configured such that when the first centering block moves backward in the Z-axis direction by the action of the first guide cylinder, the first cam guide is separated from the first pivot, and when the first centering block moves forward in the Z-axis direction by the action of the first guide cylinder, the first cam guide is coupled with the first pivot.

[0024] The welding module for the above welding robot may further include a pair of first LM rails installed on the bottom surface of the Z-axis motion frame.

[0025] The welding module for the above welding robot further includes a pair of first LM guides installed on the upper surface of the XY-axis motion frame, and the pair of first LM guides are each coupled to the corresponding first LM rail and can be slidably coupled in the X-axis direction.

[0026] The welding module for the above welding robot may further include a first drive cylinder configured to move the pair of first LM guides in the X-axis direction.

[0027] The welding module for the robot may be configured such that when the first centering block moves backward in the Z-axis direction by the action of the first guide cylinder and the first cam guide is separated from the first pivot, the pair of first LM guides can slide in the X-axis direction along the corresponding first LM rail, and when the first centering block moves forward in the Z-axis direction by the action of the first guide cylinder and the first cam guide is coupled with the first pivot, the pair of first LM guides can be fixed in position on the corresponding first LM rail.

[0028] The welding module for the above welding robot further includes a pair of second centering blocks and a pair of second guide cylinders, each installed on one side and the other side of the XY-axis motion frame, wherein the pair of second centering blocks each include a second pivot formed on a central front surface, and the pair of second guide cylinders can be configured to be coupled with the corresponding second centering block to move the corresponding second centering block in the Z-axis direction.

[0029] The welding module for the above welding robot may further include a pair of second cam guides installed one on one side and one on the other side of the welding machine mounting frame.

[0030] The welding module for the robot may be configured such that when the pair of second centering blocks moves backward in the Z-axis direction by the action of the pair of second guide cylinders, the pair of second cam guides is separated from the corresponding second pivot, and when the pair of second centering blocks moves forward in the Z-axis direction by the action of the pair of second guide cylinders, the pair of second cam guides is coupled with the corresponding second pivot.

[0031] The welding module for the above welding robot may further include a pair of second LM rails installed on one front side and the other front side of the XY-axis motion frame.

[0032] The welding module for the above welding robot further includes a pair of second LM guides installed on the rear surface of the welding machine mounting frame, and the pair of second LM guides are each coupled to the corresponding second LM rail and can be slidably coupled in the Y-axis direction.

[0033] The welding module for the above welding robot may further include a second drive cylinder configured to move or position the pair of second LM guides in the Y-axis direction.

[0034] The welding module for the robot may be configured such that when the pair of second centering blocks are moved backward in the Z-axis direction by the action of the pair of second guide cylinders and the pair of second cam guides are separated from the corresponding second pivot, the pair of second LM guides are slidable or fixed in position along the corresponding second LM rail in the Y-axis direction, and when the pair of second centering blocks are moved forward in the Z-axis direction by the action of the pair of second guide cylinders and the pair of second cam guides are coupled with the corresponding second pivot, the pair of second LM guides are fixed in position on the corresponding second LM rail.

[0035] The welding module for the above welding robot may further include a welder mounted on the welder mounting frame.

[0036] The above welding machine may include a welding torch and a mandrel.

[0037] The welding module for the above welding robot may further include a sensor mounting frame fixedly connected to the main frame.

[0038] The welding module for the above welding robot may further include a camera, a lighting device, a laser sensor, and a contact sensor mounted on the sensor mounting frame.

[0039] Another aspect of the present invention is:

[0040] robot body; and

[0041] A welding robot including a welding module for the above welding robot is provided.

[0042] The above robot body and the welding module for the welding robot can be mechanically and electrically connected to each other.

[0043] Another aspect of the present invention is:

[0044] As an automatic welding method using the above welding robot,

[0045] Step of setting welding target information, welding conditions and welding algorithm (S10);

[0046] Step (S20) of analyzing the diameter and position of the tube sheet using a laser sensor;

[0047] A step (S30) of analyzing the three-dimensional position of the tube sheet using a contact sensor;

[0048] A step (S40) of measuring the distance between the tube sheet and the welding robot using the contact sensor;

[0049] A step (S50) of analyzing the layout of tube holes formed in the tube sheet using a camera;

[0050] A step (S60) of analyzing the center of a specific tube hole among the tube holes using the camera; and

[0051] An automatic welding method is provided, including a step (S70) of analyzing the diameter of the tube sheet and updating the welding algorithm.

[0052] The above welding target information includes project information and tube sheet information, and the tube sheet information may include a diameter of a tube sheet, a diameter of a tube, the number of tube holes or the number of tubes, or the number of tubes, and a thickness of a tube.

[0053] The above welding algorithm may include the number of welding grids, the welding sequence, and the welding pattern.

[0054] The above automatic welding method may further include a step (S35) of aligning the three-dimensional position of the welding robot to the three-dimensional position of the tube sheet based on the analysis result of the step (S30).

[0055] The above automatic welding method may further include a step (S80) of moving the welding robot toward a specific tube hole of the tube sheet according to the distance measurement result of the step (S40) and the updated welding algorithm of the step (S70), but moving the welding robot so that the tube sheet and the welding robot are separated by a predetermined distance.

[0056] The above automatic welding method may further include a step (S90) of operating the welding module for the welding robot to insert a mandrel mounted on the welding machine into the specific tube hole.

[0057] The above automatic welding method may further include a step (S100) of operating the welding module for the welding robot to carefully insert the mandrel into the specific tube hole.

[0058] The above automatic welding method may further include a step (S110) of operating the welding module for the welding robot to position and fix the mandrel inserted into the specific tube hole.

[0059] The above automatic welding method may further include a step (S120) of operating a welding module for the welding robot to weld a tube inserted into the specific tube hole with the tube sheet centered on the specific tube hole.

[0060] The above automatic welding method may further include a step (S130) of moving the welding robot to the opposite side of the specific tube hole of the tube sheet, such that the tube sheet and the welding robot are spaced apart by a predetermined distance.

[0061] A welding module, a welding robot, and an automatic welding method according to one embodiment of the present invention have the following advantages.

[0062] (1) When welding a tube and a tube sheet, accurate 3D coordinates of the tube sheet can be generated to perform high-accuracy automatic welding.

[0063] (2) From the results of (1) above, the number and arrangement of tube holes (tube map) can be identified and a welding work pattern according to the scale can be set to disperse the welding force concentration.

[0064] (3) Stable mandrel positioning within the tubesheet ensures consistent weld quality and enables continuous, uninterrupted welding of multiple tubes and tubesheets. For example, by reducing the interval between tube holes to less than 1 minute and 30 seconds, work efficiency can be expected to increase by approximately 30-50% compared to conventional manual operations.

[0065] FIG. 1 is a schematic drawing of a welding robot according to one embodiment of the present invention.

[0066] Figure 2 is a drawing showing an example of a tube sheet.

[0067] FIG. 3a is a side perspective view of a welding module for a welding robot according to one embodiment of the present invention, FIG. 3b is a partially exploded perspective view of FIG. 3a, and FIG. 3c is a bottom view of FIG. 3b.

[0068] FIG. 4a is a perspective view of the other side of a welding module for a welding robot according to one embodiment of the present invention, and FIG. 4b is a partially exploded perspective view of FIG. 4a.

[0069] Fig. 5a is a drawing showing a state in which the Z-axis motion frame and the XY-axis motion frame are separated by rotating Fig. 4b counterclockwise, and Fig. 5b is a drawing showing a state in which the Z-axis motion frame and the XY-axis motion frame are combined by rotating Fig. 4a counterclockwise.

[0070] Fig. 6a is a drawing showing a state in which the Z-axis motion frame moves backward with respect to the main frame by rotating Fig. 4a counterclockwise, and Fig. 6b is a drawing showing a state in which the Z-axis motion frame moves forward with respect to the main frame by rotating Fig. 4a counterclockwise.

[0071] Figure 7 is a drawing of the left and right gripper portions of the welding module for the welding robot of Figure 3b observed from below in an upward direction (in the direction of arrow B).

[0072] Fig. 8 is a drawing showing the possible movement directions of each part of the welding module for the welding robot of Fig. 3a.

[0073] FIG. 9a is a drawing for explaining primary vision analysis and secondary vision analysis using a camera equipped in a welding module for the welding robot of FIG. 3a.

[0074] Fig. 9b is a drawing for explaining the reason for the dual analysis of primary vision analysis and secondary vision analysis using a camera equipped in the welding module for the welding robot of Fig. 3a.

[0075] Fig. 10a is a flowchart showing the process of setting the welding order and welding pattern on the display panel of the welding robot of Fig. 1.

[0076] Fig. 10b is a drawing showing an example of setting the welding order and welding pattern in the flow chart of Fig. 10a.

[0077] Figure 10c is a drawing showing a process of performing welding according to the welding order set as in Figure 10b.

[0078] Figure 11a is a flowchart showing the process of operating the welding robot of Figure 1 to correct the position of the tube sheet.

[0079] Figure 11b is a drawing for explaining the position correction step distinction process in the flow chart of Figure 11a.

[0080] Fig. 12a is a drawing showing a phenomenon in which eccentricity occurs when a mandrel equipped in a welding module for a welding robot of Fig. 4a is inserted into a tube.

[0081] Fig. 12b is a drawing showing the function of the welding module for the welding robot of Fig. 4a to automatically overcome eccentricity as in Fig. 12a and carefully place the mandrel inside the tube.

[0082] Hereinafter, a welding module and a welding robot according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0083] In this specification, “Z-axis” means horizontal axes that are parallel to a virtual horizontal axis connecting a mandrel equipped in a welding module for a welding robot and a tube sheet that is a welding target, “X-axis” means horizontal axes that are located on the same plane as the “Z-axis” and are parallel to virtual horizontal axes that are perpendicular to the “Z-axis,” and “Y-axis” means virtual vertical axes that are perpendicular to both the “Z-axis” and the “X-axis.”

[0084] Also, in this specification, "top surface" means a surface located on the upper side of a certain member based on the vertical axis, the Y-axis, and "bottom surface" means a surface located on the lower side of a certain member based on the vertical axis, the Y-axis.

[0085] Also, in this specification, the term "front" means a surface located in front of a certain member with respect to the horizontal axis, the Z-axis (i.e., the surface closest to the tube sheet), and the term "rear" means a surface located in the rear of a certain member with respect to the horizontal axis, the Z-axis (i.e., the surface farthest from the tube sheet).

[0086] Also, in this specification, “LM” is an abbreviation for “linear motion”.

[0087] Also, in this specification, “pivot” means a groove formed to be tapered so that the opening is wide.

[0088] Also, in this specification, “gripper” means a combined structure of a cam guide and a pivot.

[0089] FIG. 1 is a schematic drawing showing a welding robot (1) according to one embodiment of the present invention, and FIG. 2 is a drawing showing an example of a tube sheet (TS).

[0090] Referring to FIG. 1, a welding robot (1) according to one embodiment of the present invention includes a robot body (10) and a welding module (100) for a welding robot.

[0091] The robot body (10) and the welding module (100) for the welding robot can be mechanically and electrically connected to each other.

[0092] Additionally, the welding robot (1) can be configured to complete a tube bundle of a shell-and-tube heat exchanger (SNT) by welding a plurality of tubes (TB) to a tube sheet (TS).

[0093] In addition, the welding robot (1) may be a multi-joint robot, and may include a database (not shown) that stores and processes various data, and a control unit (not shown) that controls welding work together with the overall movement and partial movement of the robot body (10) and the welding module (100) for the welding robot in conjunction with the database.

[0094] Referring to FIGS. 1 and 2, a shell-and-tube heat exchanger (SNT) may include a tube sheet (TS), a plurality of tubes (TB), and a plurality of baffles (BF). The tube sheet (TS), the plurality of tubes (TB), and the plurality of baffles (BF) may be collectively referred to as a tube bundle.

[0095] Additionally, a plurality of tube holes (TH) can be formed in the tube sheet (TS).

[0096] FIG. 3A is a perspective view of one side of a welding module (100) for a welding robot according to an embodiment of the present invention, FIG. 3B is a partially exploded perspective view of FIG. 3A, FIG. 3C is a bottom view of FIG. 3B, FIG. 4A is a perspective view of the other side of a welding module (100) for a welding robot according to an embodiment of the present invention, FIG. 4B is a partially exploded perspective view of FIG. 4A, FIG. 5A is a view showing a state in which a Z-axis motion frame (130) and an XY-axis motion frame (140) are separated by rotating FIG. 4B in a counterclockwise direction, FIG. 5B is a view showing a state in which a Z-axis motion frame (130) and an XY-axis motion frame (140) are coupled by rotating FIG. 4A in a counterclockwise direction, and FIG. 6A is a view showing a state in which a Z-axis motion frame (130) is moved backward with respect to a main frame (110) by rotating FIG. 4A in a counterclockwise direction, and FIG. 6B is a view showing a state in which a Z-axis motion frame (130) is moved backward with respect to a main frame (110), and FIG. This is a drawing showing a state in which the Z-axis motion frame (130) is moved forward with respect to the main frame (110) by rotating 4a counterclockwise, and FIG. 7 is a drawing showing the left and right gripper parts of the welding module (100) for the welding robot of FIG. 3b observed from below in an upward direction (arrow B direction).

[0097] Referring to FIGS. 3a, 3b, 3c, 4a, 4b, 5a, 5b, 6a, 6b and 7, a welding module (100) for a welding robot according to one embodiment of the present invention includes a main frame (110), an adapter (120), a Z-axis motion frame (130), an XY-axis motion frame (140) and a welder mounting frame (150).

[0098] The main frame (110) may be referred to as a base frame.

[0099] The adapter (120) can be coupled to the main frame (110). Specifically, one end of the adapter (120) can be coupled to the main frame (110), and the other end can be coupled to the robot body (10).

[0100] The Z-axis motion frame (130) is coupled to the main frame (110) and can be coupled to be movable in the Z-axis direction.

[0101] The XY-axis motion frame (140) is coupled to the Z-axis motion frame (130) and can be coupled to be movable in the X-axis direction.

[0102] The welding machine mounting frame (150) is coupled to the XY-axis movement frame (140) and can be coupled to be movable in the Y-axis direction.

[0103] Additionally, the welding module (100) for the welding robot can be configured so that the welding machine mounting frame (150) can move in the Z-axis, X-axis, and Y-axis directions with respect to the main frame (110).

[0104] Additionally, the welding module (100) for the welding robot may further include a pair of main LM rails (LMR0).

[0105] A pair of main LM rails (LMR0) can be installed on the bottom surface of the main frame (110). Specifically, a pair of main LM rails (LMR0) can be installed on the bottom surface of the main frame (110) and extended in parallel in the Z-axis direction while being spaced apart from each other.

[0106] Additionally, the welding module (100) for the welding robot may further include a pair of main LM guides (LMG0).

[0107] A pair of main LM guides (LMG0) may be installed on the upper surface of the Z-axis motion frame (130). Specifically, the pair of main LM guides (LMG0) may be installed on the upper surface of the Z-axis motion frame (130) so as to extend in the Z-axis direction in parallel and spaced apart from each other. In addition, the pair of main LM guides (LMG0) may be coupled to a pair of main LM rails (LMR0) so as to be slidable in the Z-axis direction.

[0108] Additionally, the welding module (100) for the welding robot may further include a main drive cylinder (not shown).

[0109] The above main drive cylinder may be configured to move a pair of main LM guides (LMG0) in the Z-axis direction. The main drive cylinder may be an air cylinder, but the present invention is not limited thereto.

[0110] Also, referring to FIG. 3c, FIG. 5a and FIG. 5b, the welding module (100) for the welding robot may further include a first centering block (CB1) and a first guide cylinder (GCYL1).

[0111] The first centering block (CB1) and the first guide cylinder (GCYL1) may be installed on the bottom surface of the Z-axis motion frame (130). Specifically, the first centering block (CB1) and the first guide cylinder (GCYL1) may be installed on the bottom surface of the Z-axis motion frame (130) and may be installed in series so as to extend in the Z-axis direction.

[0112] The first centering block (CB1) may include a first pivot (PV1) formed at the central front.

[0113] The first guide cylinder (GCYL1) can be configured to be coupled with the first centering block (CB1) to move the first centering block (CB1) in the Z-axis direction.

[0114] Also, referring to FIGS. 3b, 5a and 5b, the welding module (100) for the welding robot may further include a first cam guide (CG1).

[0115] The first cam guide (CG1) can be installed on the upper surface of the XY-axis motion frame (140).

[0116] In addition, the welding module (100) for the welding robot can be configured such that when the first centering block (CB1) moves backward in the Z-axis direction by the action of the first guide cylinder (GCYL1), the first cam guide (CG1) is separated from the first pivot (PV1), and when the first centering block (CB1) moves forward in the Z-axis direction by the action of the first guide cylinder (GCYL1), the first cam guide (CG1) is coupled with the first pivot (PV1) (the operating principle is the same as that of FIG. 7).

[0117] Also, referring to FIGS. 3c, 5a and 5b, the welding module (100) for the welding robot may further include a pair of first LM rails (LMR1).

[0118] A pair of first LM rails (LMR1) may be installed on the bottom surface of the Z-axis motion frame (130). Specifically, a pair of first LM rails (LMR1) may be installed on the bottom surface of the Z-axis motion frame (130) and may be installed so as to extend in the X-axis direction in parallel and spaced apart from each other.

[0119] Also, referring to FIGS. 3b, 4b, 5a and 5b, the welding module (100) for the welding robot may further include a pair of first LM guides (LMG1).

[0120] A pair of first LM guides (LMG1) may be installed on the upper surface of the XY-axis motion frame (140). Specifically, the pair of first LM guides (LMG1) may be installed on the upper surface of the XY-axis motion frame (140) and may be installed in parallel and spaced apart from each other to extend in the X-axis direction.

[0121] A pair of first LM guides (LMG1) are each coupled to a corresponding first LM rail (LMR1) and can be coupled so as to be slidable in the X-axis direction.

[0122] Additionally, the welding module (100) for the welding robot may further include a first drive cylinder (not shown).

[0123] The first driving cylinder may be configured to move a pair of first LM guides (LMG1) in the X-axis direction. The first driving cylinder may be an air cylinder, but the present invention is not limited thereto.

[0124] In addition, the welding module (100) for the welding robot can be configured such that when the first centering block (CB1) moves backward in the Z-axis direction by the action of the first guide cylinder (GCYL1) so that the first cam guide (CG1) is separated from the first pivot (PV1), a pair of first LM guides (LMG1) can slide along the corresponding first LM rail (LMR1) in the X-axis direction, and when the first centering block (CB1) moves forward in the Z-axis direction by the action of the first guide cylinder (GCYL1) so that the first cam guide (CG1) is coupled with the first pivot (PV1), a pair of first LM guides (LMG1) can be fixed in position on the corresponding first LM rail (LMR1) (the operating principle is the same as that of FIG. 7).

[0125] Also referring to FIG. 3b, the welding module (100) for the welding robot may further include a pair of second centering blocks (CB2) and a pair of second guide cylinders (GCYL2).

[0126] A pair of second centering blocks (CB2) and a pair of second guide cylinders (GCYL2) may be installed one by one on one side and the other side of the XY-axis motion frame (140). Specifically, a pair of second centering blocks (CB2) and a pair of second guide cylinders (GCYL2) may be installed one by one on one side and the other side of the XY-axis motion frame (140), and may be installed in series so as to extend in the Z-axis direction.

[0127] Referring to FIG. 3b, FIG. 4a, and FIG. 7, each of the second centering blocks (CB2) may include a second pivot (PV2) formed at the central front surface.

[0128] A pair of second guide cylinders (GCYL2) may be configured to be coupled with a corresponding second centering block (CB2) to move the corresponding second centering block (CB1) in the Z-axis direction.

[0129] Additionally, the welding module (100) for the welding robot may further include a pair of second cam guides (CG2).

[0130] A pair of second cam guides (CG2) can be installed on one side and the other side of the welding machine mounting frame (150).

[0131] In addition, the welding module (100) for the welding robot may be configured such that when a pair of second centering blocks (CB2) move backward in the Z-axis direction by the action of a pair of second guide cylinders (GCYL2), a pair of second cam guides (CG2) are separated from a corresponding second pivot (PV2) (see (a1) and (a2) of FIG. 7), and when a pair of second centering blocks (CB2) move forward in the Z-axis direction by the action of a pair of second guide cylinders (GCYL2), a pair of second cam guides (CG2) are coupled with a corresponding second pivot (PV2) (see (b1) and (b2) of FIG. 7).

[0132] Additionally, the welding module (100) for the welding robot may further include a pair of second LM rails (LMR2).

[0133] A pair of second LM rails (LMR2) may be installed one on one front side and one on the other front side of the XY-axis motion frame (140). Specifically, a pair of second LM rails (LMR2) may be installed one on one front side and one on the other front side of the XY-axis motion frame (140), and may be installed so as to extend in the Y-axis direction.

[0134] Additionally, the welding module (100) for the welding robot may further include a pair of second LM guides (LMG2).

[0135] A pair of second LM guides (LMG2) may be installed on the back of the welder mounting frame (150). Specifically, a pair of second LM guides (LMG2) may be installed on the back of the welder mounting frame (150) and may be installed to extend in the Y-axis direction.

[0136] A pair of second LM guides (LMG2) are each coupled to a corresponding second LM rail (LMR2) and can be coupled so as to be slidable in the Y-axis direction.

[0137] Additionally, the welding module (100) for the welding robot may further include a second drive cylinder (not shown).

[0138] The second drive cylinder may be configured to move or position a pair of second LM guides (LMG2) in the Y-axis direction. The second drive cylinder may be an air cylinder, but the present invention is not limited thereto.

[0139] In addition, the welding module (100) for the welding robot may be configured such that when a pair of second centering blocks (CB2) are moved backward in the Z-axis direction by the action of a pair of second guide cylinders (GCYL2) so that a pair of second cam guides (CG2) are separated from the corresponding second pivot (PV2), a pair of second LM guides (LMG2) are slidable or positionally fixed along the corresponding second LM rail (LMR2) in the Y-axis direction (see (a1) and (a2) of FIG. 7), and when a pair of second centering blocks (CB2) are moved forward in the Z-axis direction by the action of a pair of second guide cylinders (GCYL2) so that a pair of second cam guides (CG2) are coupled with the corresponding second pivot (PV2), a pair of second LM guides (LMG2) are positionally fixed on the corresponding second LM rail (LMR2) (see (b1) and (b2) of FIG. 7).

[0140] Additionally, the welding module (100) for the welding robot may further include a welder (WLD).

[0141] The welding machine (WLD) may include a welding torch (WTC) and a mandrel (MDR).

[0142] The mandrel (MDR) is inserted into a specific tube hole (TH) to be welded and serves to fix the position of the welding module (100) for the welding robot.

[0143] The welder (WLD) may be an orbital welder.

[0144] Additionally, the welding module (100) for the welding robot may further include a sensor mounting frame (160).

[0145] Additionally, the welding module (100) for the welding robot may further include a camera (CMR), a lighting device (LF), a laser sensor (LSNR), and a contact sensor (TSNR) mounted on a sensor mounting frame (160).

[0146] FIG. 8 is a drawing showing the movable directions of each part of the welding module (100) for the welding robot of FIG. 3a. In FIG. 8, “A” is a welding machine mounting frame (150), “B” is an XY-axis movement frame (140), and “C” is a combination of a main frame (110), an adapter (120), and a Z-axis movement frame (130).

[0147] Referring to Fig. 8, when a pair of second cam guides (CG2) and a corresponding second pivot (PV2) are separated, i.e., when the left and right grippers are open, A and B can move in the Y-axis direction relative to each other.

[0148] When a pair of first cam guides (CG1) and corresponding first pivots (PV1) are separated, i.e., the upper gripper is open, B and C can move in the X-axis direction relative to each other.

[0149] When the upper gripper and the left and right grippers are open, A can move in the X-axis direction and the Y-axis direction based on C.

[0150] Hereinafter, an automatic welding method according to one embodiment of the present invention will be described in detail with reference to the drawings.

[0151] FIG. 9a is a drawing for explaining the first vision analysis and the second vision analysis using the camera equipped in the welding module for the welding robot of FIG. 3a, FIG. 9b is a drawing for explaining the reason for the dual analysis of the first vision analysis and the second vision analysis using the camera equipped in the welding module for the welding robot of FIG. 3a, FIG. 10a is a flowchart showing the process of setting the welding order and the welding pattern on the display panel of the welding robot of FIG. 1, FIG. 10b is a drawing showing an example of setting the welding order and the welding pattern in the flowchart of FIG. 10a, FIG. 10c is a drawing showing the process of performing welding according to the welding order set as in FIG. 10b, FIG. 11a is a flowchart showing the process of correcting the position of the tube sheet by operating the welding robot of FIG. 1, FIG. 11b is a drawing for explaining the position correction step distinction process in the flowchart of FIG. 11a, and FIG. 12a is a drawing for explaining the process of causing eccentricity when inserting the mandrel equipped in the welding module for the welding robot of FIG. 4a into the tube. This is a drawing showing the phenomenon, and Fig. 12b is a drawing showing the function (centering function) of the welding module for the welding robot of Fig. 4a to automatically overcome eccentricity as in Fig. 12a and keep the mandrel inside the tube.

[0152] An automatic welding method according to one embodiment of the present invention includes a step of setting information on a welding object, welding conditions, and a welding algorithm (S10), a step of analyzing a diameter and a position of a tube sheet using a laser sensor (S20), a step of analyzing a three-dimensional position of the tube sheet using a contact sensor (S30), a step of measuring a distance between the tube sheet and the welding robot using the contact sensor (S40), a step of analyzing a layout of tube holes formed in the tube sheet using a camera (S50), a step of analyzing a center of a specific tube hole among the tube holes using the camera (S60), and a step of analyzing the diameter of the tube sheet and updating the welding algorithm (S70).

[0153] In the above step (S10), the welding target information includes project information and tube sheet information, and the tube sheet information may include the diameter of the tube sheet, the diameter of the tube, the number of tubes or the number of tube holes, and the thickness of the tube.

[0154] Additionally, in the above step (S10), the welding algorithm may include the number of welding grids, the welding order, and the welding pattern (see FIG. 10b).

[0155] The above step (S20) may be performed according to the order shown in Fig. 11a. In Fig. 11a, “servo ON” means operation of the thermocouple for moving the robot arm as needed.

[0156] Referring to FIG. 11b in relation to the position correction step distinction process of FIG. 11a, the laser sensor is moved horizontally to detect three outer points (P1, P2, P3) of the shell-and-tube type heat exchanger (see (a) of FIG. 11b), and the position and size of the shell-and-tube type heat exchanger are identified based on the three detected outer points (see (b) of FIG. 11b).

[0157] The above step (S30) is a step for measuring the degree to which the smooth surface of the tube sheet (TS) is tilted with respect to a virtual vertical plane (i.e., the offset value) through a three-point touch. Specifically, based on the diameter of the shell-and-tube heat exchanger and the diameter information of the tube sheet pre-input in the work information, the diameter of the tube sheet based on the diameter of the detected shell-and-tube heat exchanger is calculated, and then the three-point position correction coordinates (P1', P2', P3') are regenerated from the calculated diameter and offset value of the tube sheet (see (c) of Fig. 11b). Thereafter, the position correction work is performed based on the regenerated position correction coordinates (P1', P2', P3').

[0158] In addition, the automatic welding method may further include a step (S35) of aligning the three-dimensional position of the welding robot (1) to the three-dimensional position of the tube sheet (TS) according to the analysis result of the step (S30). Specifically, in the step (S35), the welding robot (1) (specifically, the welding module (100) for the welding robot) may be tilted to the extent that the smooth surface of the tube sheet (TS) is tilted with respect to the virtual vertical plane. That is, in the step (S35), the posture of the welding robot (1) may be changed so as to match the smooth surface of the tube sheet (TS).

[0159] The above step (S50) is a step of generating a tube map in which the number and location of tube holes are verified by first photographing the tube sheet (TS) in a Z-shaped path using a camera (CMR) (see (a) of FIG. 9b) and (b) of FIG. 9a). However, the generated tube map has a problem in that distortion of the tube hole center due to optical measurement remains (see (c) of FIG. 9b).

[0160] The above step (S60) is a step for re-photographing a specific tube hole to be welded using a camera (CMR) to eliminate distortion of the center of the tube hole created in the above step (S50) (see (b) of Fig. 9a).

[0161] The above step (S70) may be a step for automatically updating the welding algorithm based on the analysis results of the above step (S50) and the analysis results of the above step (S60), or may be a step for a user to manually update the welding algorithm based on the order shown in FIG. 10a.

[0162] In addition, the automatic welding method may further include a step (S80) of moving the welding robot (1) toward a specific tube hole (TH) of the tube sheet (TS) according to the distance measurement result of the step (S40) and the updated welding algorithm of the step (S70), such that the tube sheet (TS) and the welding robot (1) (specifically, the tip of the mandrel (MDR)) are spaced apart by a predetermined distance.

[0163] In addition, the automatic welding method may further include a step (S90) of operating a welding module (100) for a welding robot to insert a mandrel (MDR) mounted on a welding machine (WLD) into a specific tube hole (TH) (see (a) of FIG. 12a).

[0164] The above step (S90) can be performed by operating the main drive cylinder to advance a pair of main LM guides (LMG0) in the Z-axis direction by a predetermined distance (see Fig. 6b).

[0165] In addition, the above step (S90) can be performed in a state where the tube sheet (TS) and the welding robot (1) (specifically, the tip of the mandrel (MDR)) are spaced apart by a predetermined distance.

[0166] In addition, the above step (S90) can be performed in a state where the upper gripper and the left and right grippers are open (i.e., a pair of first cam guides (CG1) and the corresponding first pivot (PV1) are separated, and a pair of second cam guides (CG2) and the corresponding second pivot (PV2) are separated).

[0167] Also, referring to (a) and (b) of Fig. 12a, it can be confirmed that the center of the mandrel (MDR) does not coincide with the center of the tube (TB). Here, (a) of Fig. 12a is a side cross-sectional view, and (b) of Fig. 12a is a front view.

[0168] If, instead of performing the above steps (S80) and (S90) sequentially by separating them from each other, the welding robot (1) is continuously moved to attempt to insert the mandrel (MDR) into a specific tube hole (TH) of the tube sheet (TS) at once, the possibility of success is very low, and this is a fact confirmed by the inventors through numerous trials and errors.

[0169] In addition, the automatic welding method may further include a step (S100) of centering a mandrel (MDR) inserted into a specific tube hole (TH) by operating a welding module (100) for a welding robot (see FIG. 12b).

[0170] The above step (S100) can be performed in a state in which the upper gripper and the left and right grippers are open, similar to the above step (S90) (i.e., a pair of first cam guides (CG1) and the corresponding first pivot (PV1) are separated, and a pair of second cam guides (CG2) and the corresponding second pivot (PV2) are separated).

[0171] In addition, the above step (S100) can be performed by the upper gripper and the lower gripper mechanically operating on their own when the mandrel (MDR) collides with the wall of the tube (TB) without separate automatic control or manual operation.

[0172] In addition, the automatic welding method may further include a step (S110) of operating a welding module (100) for a welding robot to position and fix a mandrel (MDR) inserted into a specific tube hole (TS).

[0173] The above step (S110) can be performed by closing the upper gripper and the left and right grippers (i.e., by combining a pair of first cam guides (CG1) and a corresponding first pivot (PV1), and also by combining a pair of second cam guides (CG2) and a corresponding second pivot (PV2)).

[0174] In addition, the automatic welding method may further include a step (S120) of operating a welding module (100) for a welding robot (specifically, a welding machine (WLD)) to weld a tube (TB) inserted into a specific tube hole (TH) with a tube sheet (TS) centered on the specific tube hole (TH).

[0175] In addition, the automatic welding method may further include a step (S125) of stopping welding by prioritizing the operation of the welding module (100) for the welding robot (specifically, the welder (WLD)). Specifically, the automatic welding method may be configured to perform automatic welding from step 1 to the end according to a welding algorithm during normal operation, but to stop the welding operation when necessary. More specifically, a user may stop the welding operation (holding system), or the welding robot may automatically stop the welding operation according to logic after determining a welding defect (emergency system). For example, if the holding system is activated during welding of the 6th tube hole, the welding operation of the 7th tube hole will not be additionally performed even if the welding of the 6th tube hole is completed. As another example, if the welding operation of the 6th tube hole is performed but the welding robot determines that the welding was not performed properly, it regards it as a "welding operation abnormality", outputs a message for the operator to confirm, and stops the welding operation.

[0176] In addition, the automatic welding method may further include a step (S130) of moving the welding robot to the opposite side of the specific tube hole of the tube sheet, such that the tube sheet and the welding robot are spaced apart by a predetermined distance.

[0177] The above step (S130) can be performed by operating the main drive cylinder to move a pair of main LM guides (LMG0) backward by a predetermined distance in the Z-axis direction (see Fig. 6a).

[0178] In addition, the automatic welding method may be configured to repeat the steps (S60) and (S90) to (S130) in this order for other tube holes other than the specific tube hole.

[0179] While the present invention has been described with reference to the drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent implementations are possible. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the appended claims.

[0180] [Explanation of symbols]

[0181] 1: Welding robot 10: Robot body

[0182] 100: Welding module for welding robot 110: Main frame

[0183] 120: Adapter 130: Z-axis motion frame

[0184] 140: XY-axis movement frame 150: Welding machine mounting frame

[0185] 160: Sensor mounting frame SNT: Shell-and-tube type heat exchanger

[0186] TS: Tubesheet TH: Tubehole

[0187] TB: Tube BF: Baffle

[0188] LMR0, LMR1, LMR2: LM rail LMG0, LMG1, LMG2: LM guide

[0189] WLD: Welding machine WTC: Welding torch

[0190] MDR: Mandrel CMR: Camera

[0191] TSNR: Contact sensor LSNR: Laser sensor

[0192] LF: Lighting fixture CG1, CG2: Cam guide

[0193] CB1, CB2: Centering block GCYL1, GCYL2: Guide cylinder

[0194] PV1, PV2: Pivot

Claims

1. Mainframe; An adapter coupled to the above main frame; A Z-axis motion frame coupled to the above main frame and capable of moving in the Z-axis direction; An XY-axis motion frame coupled to the Z-axis motion frame but movable in the X-axis direction; and Includes a welding machine mounting frame coupled to the above XY-axis motion frame and movable in the Y-axis direction, A welding module for a welding robot wherein the Z-axis, the X-axis and the Y-axis are perpendicular to each other.

2. In paragraph 1, The welding module for the above welding robot is a welding module for the welding robot configured such that the welding machine mounting frame can move in the Z-axis, X-axis, and Y-axis directions with respect to the main frame.

3. In paragraph 1, A welding module for a welding robot further comprising a pair of main LM rails installed on the bottom surface of the main frame.

4. In paragraph 3, A welding module for a welding robot further comprising a pair of main LM guides installed on the upper surface of the Z-axis motion frame, wherein the pair of main LM guides are each coupled to the corresponding main LM rails and are slidably coupled in the Z-axis direction.

5. In paragraph 4, A welding module for a welding robot further comprising a main drive cylinder configured to move the pair of main LM guides in the Z-axis direction.

6. In paragraph 1, A welding module for a welding robot, further comprising a first centering block and a first guide cylinder installed on the lower surface of the Z-axis motion frame, wherein the first centering block includes a first pivot formed on the central front, and the first guide cylinder is coupled with the first centering block to move the first centering block in the Z-axis direction.

7. In paragraph 6, A welding module for a robot further comprising a first cam guide installed on the upper surface of the XY-axis motion frame.

8. In paragraph 7, A welding module for a robot, wherein the first cam guide is separated from the first pivot when the first centering block moves backward in the Z-axis direction by the action of the first guide cylinder, and the first cam guide is coupled with the first pivot when the first centering block moves forward in the Z-axis direction by the action of the first guide cylinder.

9. In paragraph 8, A welding module for a welding robot further comprising a pair of first LM rails installed on the bottom surface of the Z-axis motion frame.

10. In paragraph 9, A welding module for a welding robot further comprising a pair of first LM guides installed on the upper surface of the XY-axis motion frame, wherein the pair of first LM guides are each coupled to the corresponding first LM rails and are slidably coupled in the X-axis direction.

11. In paragraph 10, A welding module for a welding robot further comprising a first drive cylinder configured to move the pair of first LM guides in the X-axis direction.

12. In paragraph 10, A welding module for a welding robot, wherein the first centering block moves backward in the Z-axis direction by the action of the first guide cylinder so that the first cam guide is separated from the first pivot, and the pair of first LM guides is slidable in the X-axis direction along the corresponding first LM rail, and the first centering block moves forward in the Z-axis direction by the action of the first guide cylinder so that the first cam guide is coupled with the first pivot, and the pair of first LM guides is fixed in position on the corresponding first LM rail.

13. In paragraph 1, A welding module for a welding robot, further comprising a pair of second centering blocks and a pair of second guide cylinders, each installed on one side and the other side of the XY-axis motion frame, wherein the pair of second centering blocks each include a second pivot formed on a central front surface, and the pair of second guide cylinders are each configured to be coupled with the corresponding second centering block to move the corresponding second centering block in the Z-axis direction.

14. In paragraph 13, A welding module for a robot further comprising a pair of second cam guides installed on one side and the other side of the welding machine mounting frame.

15. In paragraph 14, The welding module for the robot is configured such that when the pair of second centering blocks moves backward in the Z-axis direction by the action of the pair of second guide cylinders, the pair of second cam guides is separated from the corresponding second pivot, and when the pair of second centering blocks moves forward in the Z-axis direction by the action of the pair of second guide cylinders, the pair of second cam guides is coupled with the corresponding second pivot.

16. In paragraph 15, A welding module for a welding robot further comprising a pair of second LM rails installed on one front side and the other front side of the XY-axis motion frame.

17. In paragraph 16, A welding module for a welding robot further comprising a pair of second LM guides installed on the back surface of the welding machine mounting frame, wherein the pair of second LM guides are each coupled to the corresponding second LM rails and are slidably coupled in the Y-axis direction.

18. In paragraph 17, A welding module for a welding robot further comprising a second drive cylinder configured to move or position the pair of second LM guides in the Y-axis direction.

19. In paragraph 17, A welding module for a welding robot, wherein the pair of second centering blocks are moved backward in the Z-axis direction by the action of the pair of second guide cylinders so that the pair of second cam guides are separated from the corresponding second pivot, and the pair of second LM guides are slidable or fixed in position along the corresponding second LM rail in the Y-axis direction, and the pair of second centering blocks are moved forward in the Z-axis direction by the action of the pair of second guide cylinders so that the pair of second cam guides are coupled with the corresponding second pivot, and the pair of second LM guides are fixed in position on the corresponding second LM rail.

20. In paragraph 1, A welding module for a welding robot further comprising a welder mounted on the above welding machine mounting frame.

21. In paragraph 20, The above welding machine is a welding module for a welding robot including a welding torch and a mandrel.

22. In paragraph 1, A welding module for a welding robot further comprising a sensor mounting frame fixedly connected to the main frame.

23. In paragraph 22, A welding module for a welding robot further comprising a camera, a lighting device, a laser sensor and a contact sensor mounted on the above sensor mounting frame.

24. Robot body; and A welding robot comprising a welding module for a welding robot according to any one of claims 1 to 23.

25. In paragraph 24, A welding robot in which the robot body and the welding module for the welding robot are mechanically and electrically connected to each other.

26. An automatic welding method using a welding robot according to Article 24, Step of setting welding target information, welding conditions and welding algorithm (S10); Step (S20) of analyzing the diameter and position of the tube sheet using a laser sensor; A step (S30) of analyzing the three-dimensional position of the tube sheet using a contact sensor; A step (S40) of measuring the distance between the tube sheet and the welding robot using the contact sensor; A step (S50) of analyzing the layout of tube holes formed in the tube sheet using a camera; A step (S60) of analyzing the center of a specific tube hole among the tube holes using the camera; and An automatic welding method including a step (S70) of analyzing the diameter of the tube sheet and updating the welding algorithm.

27. In paragraph 26, An automatic welding method wherein the above welding target information includes project information and tube sheet information, and the tube sheet information includes a diameter of the tube sheet, a diameter of the tube, a number of tubes, and a thickness of the tube.

28. In paragraph 26, The above welding algorithm is an automatic welding method including the number of welding grids, welding sequence and welding pattern.

29. In paragraph 26, An automatic welding method further comprising a step (S35) of aligning the three-dimensional position of the welding robot to the three-dimensional position of the tube sheet according to the analysis result of the above step (S30).

30. In paragraph 26, An automatic welding method further comprising a step (S80) of moving the welding robot toward a specific tube hole of the tube sheet according to the distance measurement result of the step (S40) and the updated welding algorithm of the step (S70), such that the tube sheet and the welding robot are separated by a predetermined distance.

31. In paragraph 30, An automatic welding method further comprising a step (S90) of operating the welding module for the welding robot to insert a mandrel mounted on the welding machine into the specific tube hole.

32. In paragraph 31, An automatic welding method further comprising a step (S100) of operating a welding module for the welding robot to carefully insert the mandrel into the specific tube hole.

33. In paragraph 32, An automatic welding method further comprising a step (S110) of operating a welding module for the welding robot to position and fix the mandrel inserted into the specific tube hole.

34. In paragraph 33, An automatic welding method further comprising a step (S120) of operating a welding module for the welding robot to weld a tube inserted into the specific tube hole with the tube sheet centered on the specific tube hole.

35. In paragraph 34, An automatic welding method further comprising a step (S130) of moving the welding robot to the opposite side of the specific tube hole of the tube sheet so that the tube sheet and the welding robot are spaced apart by a predetermined distance.

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