JP2005169489A - Welding system using obliquely moving articulated robot as auxiliary robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new welding system that can reduce an operator's burden by enabling a robot to efficiently perform an auxiliary work with the purpose of preparing an environment for a welding robot to carry out desired welding, that can efficiently deal with change in a workpiece by a robot as a generally applicable welding system, and that can improve the working time of the welding robot, in a welding system in which a first and a second workpiece held in a prescribed attitude are integrally welded using a welding robot. <P>SOLUTION: In the obliquely moving articulated robot in use for the system, there are alternately arranged, as an auxiliary robot 10, a section with a plurality of articulated arms A1-A7 connected via first pivot shafts 15, 15A, 15B which are horizontal turning pivot, and a section with these arms connected via second pivot shafts 32, 32A 32B which are inclined turning pivots, while a motor M for driving each turning pivot and a speed reduction mechanism are arranged for each turning pivot. At the tip end of this obliquely moving articulated robot 10, there is mounted a workpiece holding tool 60 to which a second workpiece 96 is attached. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a welding system using a welding robot, and in particular, reduces the burden on an operator when welding and integrating a first workpiece and a second workpiece held in a predetermined posture using a welding robot. The present invention relates to an improved welding system that can reduce the number of work steps and can be generalized as a system.

  It is widely used in automobile assembly factories and the like to weld and integrate a first workpiece and a second workpiece held in a predetermined posture using an industrial welding robot. When the first workpiece is a large-sized object such as a floor portion of an automobile and the second workpiece is a small item attached to the floor portion, in a normal welding system, the floor portion (the first portion is placed on the pedestal in the work area. The workpiece is supported, and the operator carries a plurality of kinds of small articles (second workpiece) to the predetermined position for positioning. After positioning, the clamp-dedicated jig clamps (fixes) all the second workpieces to the first workpiece at the same time, and in this state, the welding robot takes a predetermined movement locus and welds them together. . After completion of the welding process, the clamp dedicated jig is unclamped, and the product after welding is taken out from the work area.

  In order to simplify the work of positioning the second workpiece manually by the operator, the positioning and fixing (clamping) of the second workpiece with respect to the first workpiece are simultaneously performed using the handling robot mechanism. The technique to do is described in patent document 1 (Unexamined-Japanese-Patent No. 2003-146264). A method for positioning a workpiece in which a welding robot is also used as a positioning means is described in Patent Document 2 (Japanese Patent Laid-Open No. 11-90641). In any case, a certain amount of labor saving in the entire welding system can be expected by using it.

  When welding a relatively large number of workpieces, position the workpieces on the base using positioning pins, etc. The welding robot moves along a predetermined trajectory in a state where all the nearby parts are clamped at the same time, and the required welding is continuously performed.

JP 2003-146264 A Japanese Patent Laid-Open No. 11-90641

  As described above, in a conventional welding system using an industrial welding robot, an operator performs a manual operation on a first workpiece set on a pedestal in a work area before the welding robot performs a welding operation. It requires operations such as carrying and positioning a plurality of second workpieces by work, and then clamping (fixing) all the second workpieces to the first workpiece using a clamp-dedicated jig. The burden on the person is great. In addition, the clamp-dedicated jig lacks versatility, and it is necessary to recreate a clamp-dedicated jig every time the workpiece is changed. Furthermore, in order to ensure the safety of the operator, the welding robot starts the welding operation after all the workpieces are clamped, and the operating time of the welding robot has to be limited.

  If the industrial robot can assist the operations associated with the welding operation of the welding robot, the above inconveniences can be easily eliminated. However, industrial robots used so far in assembly factories cannot be used as auxiliary robots in welding systems as they are. The reason for this is that conventional industrial robots are polar-coordinate articulated robots, that is, as shown in FIG. A multi-joint robot in which the second arm 2 is swingably attached to the tip and a multi-directional wrist mechanism 4 is provided at the tip is the mainstream, and such a polar coordinate articulated robot itself is the mainstream. In addition to the large size, since the number of joints is small, the dead space due to the bending of the first arm 1 and the second arm 2 becomes large in the operation area close to the robot. Therefore, a robot that entrusts auxiliary work to a polar coordinate articulated robot in a welding area, which is a limited work space (for example, positioning work and clamping work of a second work with respect to a first work). It is practically impossible to arrange the robot as an auxiliary robot, both from the viewpoint of the actual work of the robot and from the aspect of securing the space in the work area.

  Patent Document 1 describes a handling robot mechanism that can simultaneously perform positioning and fixing (clamping) work. However, a control robot that moves the handling robot mechanism itself along a predetermined locus is a conventional polar-coordinate articulated joint. If it is a robot, the inconvenience in terms of securing space is the same as in the prior art. In addition, because of its configuration, the handling robot mechanism must be a dedicated jig in the assembly process, and lacks versatility. Therefore, when assembling different parts, each time a handling robot is fitted. Need to make. This is the same as that described in Patent Document 2. Here, since the conventional polar coordinate articulated robot is used, the work area of the robot arm is limited, and the actual work of the robot is limited. It is extremely difficult to accomplish this smoothly.

  The present invention has been made in view of the above circumstances, and in a welding system for welding and integrating a first workpiece and a second workpiece held in a predetermined posture using a welding robot. , To reduce the burden on the operator by enabling the robot to efficiently perform auxiliary work to prepare an environment in which the welding robot can perform welding as expected, even when the work to be welded changes, The purpose of the present invention is to provide a versatile welding system that enables the robot to effectively cope with it, and to provide a new welding system that can improve the operation time of the welding robot. .

  A welding system according to the present invention is a welding system for welding and integrating a first workpiece and a second workpiece held in a predetermined posture using a welding robot. An auxiliary robot that assists in performing the welding as described above, and the auxiliary robot includes a portion where the joint arms are connected to each other via the first rotation axis, and an axis of the first rotation axis. Each having at least one place connected via a second swivel axis having a tilted axial center line, and a motor and a speed reduction mechanism for driving each swivel axis are arranged for each swivel axis. It is a tilting articulated robot having the structure described above.

  The above-mentioned tilting articulated robot is provided with a motor as a drive source and a speed reduction mechanism for each joint, and the drive mechanism and power transmission mechanism of the entire robot are extremely simplified and slimmed. Then, for example, the joint arm connected by the first turning axis which is a horizontal turning axis is connected by the second turning axis (inclined turning axis) having an axis center inclined to the axis of the first turning axis. Preferably, a plurality of articulated arms are alternately connected to constitute the entire arm, and includes a conventional first arm and second arm as shown in FIG. Compared with the robot, the dead space in the work area can be reduced. Therefore, it becomes possible to arrange many robots close to each other, and the degree of freedom with respect to the environment in which the robots are used increases.

  In the above-mentioned tilting articulated robot, the inclination angle of the second turning axis with respect to the axis of the first turning axis is not particularly limited, but is preferably 45 degrees. In addition, as described above, arranging a plurality of joint arms so that the first pivot axis and the second pivot axis are alternately positioned is the position of the tool hand attached to the tip of the arm in the three-dimensional space. Although it is preferable from the viewpoint of facilitating the control, for example, two or more connecting portions by the second turning axis (inclined turning axis) may be continued according to the use environment of the robot. In that case, the inclination angle of the second turning axis with respect to the first turning axis can be made different for each second turning axis.

  As described above, the newly developed tilting articulated robot is articulated, has a wide operating range, and is slim overall. Therefore, it is possible to place a plurality of tilting articulated robots in a limited space, and without affecting the movement of the welding robot in the limited space at the welding site or from the welding robot. For example, the tip of the arm can be easily moved to any location such as around or on the first work supported by the pedestal without being affected.

  As a result, it is possible to entrust auxiliary work, which has traditionally relied solely on the manual work of the worker, to the newly-developed tilting articulated robot, greatly reducing the burden on the worker and improving work safety. Will also improve. In addition, even when the work piece (first work, second work) is changed, the tilting articulated robot can easily cope with it and becomes a versatile welding system. Moreover, since the time for the operator to enter the welding area can be reduced, the operation time of the welding robot can be improved as a result.

  As a more specific aspect of the present invention, the tilting articulated robot as the auxiliary robot is provided with a workpiece holding jig that holds the second workpiece at the tip, and the tilting articulated robot moves the first by the movement. By carrying out the steps of conveying and positioning the second workpiece to a predetermined position of the workpiece and fixing the workpiece at that position, it assists the welding robot to perform the intended welding. This conveyance, positioning, and fixing work can be easily and reliably performed because the auxiliary robot to be used is the above-described tilting articulated robot. In this state, the welding robot is operated in the same manner as in the prior art, and the second workpiece is welded to the first workpiece.

  The welding system of this aspect is suitably used when the first workpiece is a large one and the second workpiece is a small part that is welded thereon. Preferably, a small component (second workpiece) mounting area is placed in the vicinity of the welding area, and one worker holds one workpiece holding jig provided at the tip of the tilting articulated robot. Alternatively, a plurality of second workpieces are mounted. This mounting can be performed by operating the tilting articulated robot so that the work holding jig can be easily operated, and the burden on the operator during mounting is greatly reduced.

  When the workpiece holding jig holds two or more types of second workpieces, the auxiliary robot is operated as in the case of the first second workpiece, and the second second workpiece is moved to the second workpiece. It is transported to a predetermined position of one workpiece and positioned and fixed. Then, welding is performed by a welding robot. Thereafter, the same operation is performed for all the second workpieces. In this way, the auxiliary robot can effectively assist the welding robot in performing the welding as expected without using a clamp-dedicated jig as in the prior art.

  In addition, by using the newly developed tilting articulated robot, when the first workpiece is different, when the second workpiece is different, the first and second Even if both of the two workpieces are different, all of them can be easily handled by replacing the workpiece holding jig when necessary and changing the control program of the auxiliary robot. For this reason, it is possible to make the welding system highly versatile and reduce the cost of the entire welding system. Preferably, two or more kinds of work holding jigs are prepared so that the above generalization can be applied in a wider range, and different kinds of work holding jigs are attached to the tip of the tilting articulated robot as an auxiliary robot. Make sure you can wear it selectively.

  In the welding system of the present invention, as described above, it is preferable that the tilting articulated robot, which is an auxiliary robot, separates the area where the second workpiece is mounted on the workpiece holding jig and the work area of the welding robot. . In that case, since the welding system of the present invention does not require a dedicated clamping device as in the prior art, the tilting articulated robot cooperates with the welding robot to weld the second workpiece to the first workpiece. It is possible to safely perform the work of mounting the second workpiece on another workpiece holding jig in the mounting area while assisting the welding, and the actual operation time of the welding robot can be improved. . When two or more auxiliary robots are used for the second workpiece, one of the auxiliary robots is allowed to cooperate with the welding robot while the other auxiliary robot uses a workpiece holding jig. By performing the operation of mounting the second workpiece in the mounting area, the actual operation time of the welding robot can be improved in the same manner.

  In the above, when welding a small part (second workpiece) to a large first workpiece, the auxiliary robot which is a tilting articulated robot assists the welding robot (conveys the second workpiece) However, the following usage mode of the auxiliary robot is also effective in terms of work efficiency and generalization.

  That is, the tip of the tilting articulated robot that is an auxiliary robot is provided with a clamp, the auxiliary robot is moved following the movement of the welding robot, and the first workpiece and the second workpiece are moved near the welding point. Operate to clamp. And the welding robot welds the welding point which adjoins in the state clamped by the auxiliary robot. When there are a plurality of welding points, the auxiliary robot is caused to repeat this clamping process for each welding point.

  As described above, when welding a plurality of relatively large workpieces, a plurality of workpieces have been positioned on a pedestal using a positioning pin or the like so far. The welding robot performs the required welding with all the points to be welded clamped at the same time. However, in the present invention, the above-described tilting articulated robot is used as the auxiliary robot. It is possible to clamp only this point, and the clamp-dedicated jig that has been necessary in the past can be omitted. In addition, since the clamp itself is movable in this aspect, even if the first and second workpieces are changed, it can be appropriately handled by the same auxiliary robot only by changing the control program. Reduction is achieved.

  In the welding system of the present invention, in addition to the auxiliary robot described above, the tilting articulated robot can be used as a second auxiliary robot for supporting the first workpiece. Further, the above-described tilting articulated robot may be used as the welding robot.

  In the welding system of the present invention, since the auxiliary robot efficiently performs the auxiliary work for preparing the environment in which the welding robot can perform the welding as expected, the burden on the operator is greatly reduced and the safety is ensured. Also improves. In addition, even when the workpiece is changed, the auxiliary robot can effectively cope with it, so that a versatile welding system can be obtained. Furthermore, since the number of times an operator enters the welding area can be reduced, the operating time of the welding robot can be improved and the welding efficiency can be increased.

  Hereinafter, the present invention will be described by way of embodiments. First, a tilting articulated robot that is effectively used as an auxiliary robot in the welding system of the present invention will be described. 1 and 2 show an embodiment of a tilting articulated robot 10. In this example, the number of joints is six and the number of joint arms is seven. The first joint arm A1 is fixed to the base G and functions as a machine base, and includes a motor M1 as a drive source and an introduction hole 11 for cables. The motor M1 is of a type having a built-in encoder and brake device. The rotary drive shaft 12 is oriented in the horizontal direction and a bevel gear 13 is attached to the tip thereof.

  A hollow fixed shaft 14 is erected in the vertical direction on the first joint arm A1 and corresponds to a horizontal swing shaft (corresponding to the “first swing shaft” in the present invention) so as to be fitted on the shaft 14. Yes) 15 is installed. A bevel gear 16 is attached to the lower end of the horizontal turning shaft 15 and meshes with a bevel gear 13 attached to the rotational drive shaft 12 of the motor. The meshing between the bevel gear 13 and the bevel gear 16 forms one speed reduction mechanism. As well shown in the enlarged view of FIG. 2, the upper end surface of the first joint arm A1 is concentric with the axis L1 of the hollow fixed shaft 14 (which is also the axis of the horizontal turning shaft 15). The outer race B1 of the bearing B is fixed. On the other hand, the inner race B2 of the bearing B is fixed to the horizontal turning shaft 15 side through appropriate means, and the upper end of the second joint arm A2 having a cylindrical shape via a thrust bearing 17 or the like is attached to the upper end thereof. The lower end surface 21 is fixed. Therefore, when the motor M1 is rotationally driven, the rotation is transmitted to the horizontal turning shaft 15 via the bevel gear 13 and the bevel gear 16, and the second joint arm A2 rotates within a range of 360 degrees. The portion of the horizontal turning shaft 15 constitutes a first joint.

  The second joint arm A2 has a cylindrical shape, and an upper end surface is formed by an inclined surface 22 inclined at 45 degrees with respect to its axis (corresponding to the axis L1), and a horizontal plane 23 following the inclined surface 22. And has a space 24 inside. Note that the horizontal surface 23 is used to keep the height of the second joint arm A2 low, and if there is no height restriction, the entire upper end surface may be the inclined surface 22.

  On the second joint arm A2, there is located a cylindrical third joint arm A3 whose lower end surface is an inclined surface 31 inclined at 45 degrees with respect to its axis. In the second joint arm A2 and the third joint arm A3, the inclined surface 22 and the inclined surface 31 are inclined at 45 degrees with respect to the axial center line L1 and intersect with the axial center line L1. An inclined swivel shaft having L2 (corresponding to a “second swivel shaft” in the present invention) 32 is connected so as to be relatively rotatable.

  That is, an opening 25 having a center line L2 as a center line is formed in the inclined surface 22 of the second joint arm A2, and a bearing B similar to the bearing B described above is formed on a concentric circle of the center line L2. The inner race B2 is fixed. On the other hand, on the inclined surface 31 of the third joint arm A3, a hollow fixed shaft 33 centering on the axis L2 is attached in a direction perpendicular to the inclined surface 31, and the fixed shaft 33 is The space 24 of the two joint arms A2 is reached. An inclined swivel shaft 32 is attached so as to be externally fitted to the fixed shaft 33, and a gear 34 is attached to the upper end (the third joint arm A3 side). The outer peripheral portion of the inclined turning shaft 32 is integrated with the outer race B1 of the bearing B fixed to the inclined surface 31 of the third joint arm A3 through appropriate means.

  A motor M2 is provided in the third joint arm A3, and the gear 35 and the gear 34 attached to the rotation drive shaft of the motor M2 are engaged with each other. Therefore, when the motor M2 is driven to rotate, the rotation is transmitted to the inclined turning shaft 32 via the gear 35 and the gear 34, whereby the third joint arm A3 is relatively moved with respect to the second joint arm A2. It can rotate in the range of 360 degrees. The portion of the inclined turning shaft 32 constitutes a second joint.

  The upper end surface of the third joint arm A3 is a horizontal plane 36, to which the horizontal turning shaft 15A is mounted in substantially the same manner as the upper end surface of the first joint arm A1. That is, an opening 37 is formed at the center of the horizontal plane 36, and the center line thereof is made to coincide with the axis L1 when the entire tilting articulated robot is in a vertical posture as shown in the figure. The A hollow fixed shaft 14A centering on the axial center line of the opening 37 is fixed in the vertical direction, and a horizontal turning shaft 15A is mounted so as to be externally fitted to the fixed shaft 14A.

  A gear 16A is attached to the lower end of the horizontal turning shaft 15A, and meshes with a gear (not shown in FIGS. 1 and 2) attached to the rotation drive shaft of the motor M3 mounted in the third joint arm A3. Yes. The outer race B1 of the bearing B is fixed to the upper end horizontal surface 36 of the third joint arm A3 on a concentric circle with the axis of the fixed shaft 14A, and the inner race B2 of the bearing B is formed on the outer periphery of the horizontal turning shaft 15A. It is fixed via appropriate means. A fourth joint arm A4 having the same configuration as that of the second joint arm A2 is similarly fixed to the upper end of the horizontal turning shaft 15A via a thrust bearing 17A. Therefore, when the motor M3 is driven to rotate, the rotation is transmitted to the horizontal turning shaft 15A via the gear and the gear 16A, and the fourth joint arm A4 is rotated 360 degrees relative to the third turning arm A3. Rotate in range. This horizontal turning shaft 15A constitutes a third joint.

  On the fourth turning arm A4, a fifth turning arm A5 having the same configuration as that of the third turning arm A3 is arranged in the same manner, and the portion of the inclined turning shaft 32A connecting the both has the fourth joint. Constitute. Further, a sixth joint arm A6 having the same configuration as that of the second joint arm A2 is again arranged on the fifth turning arm A5, and the portion of the horizontal turning shaft 15B connecting the two is as follows. Configure the fifth joint. Then, on the sixth joint arm A6, the seventh swivel arm A7 having a configuration in which the horizontal swivel shafts 15A, 15B at the upper ends thereof are removed from the third or fifth swivel arm A3, A5 to form a flat surface 50. Are arranged in the same manner, and the portion of the inclined turning shaft 32B connecting the both constitutes the sixth joint. The flat surface 50 of the seventh turning arm A7 is a tool hand attachment surface, and tools such as a workpiece holding jig, a clamp mechanism, and a welding mechanism are attached thereto, and a tilting articulated robot 10 having six joints is provided. Is done.

  In FIG. 1 and FIG. 2, C is a cable, piping, and wiring necessary for the operation of the tilting articulated robot 10, and is necessary through the space in each joint arm and the hollow portion formed in each swivel axis. You will be guided to where you are. With this configuration, the cables and wirings are not located outside the joint arm, and the risk of the cables coming into contact with devices around the tilting articulated robot can be avoided. Of course, the cables can be arranged without using the above-described hollow portion. In that case, the hollow part formed in each turning axis becomes unnecessary.

  In the above form, the third and fifth joint arms A3 and A5 accommodate two drive motors (for example, M2 and M3) for the horizontal pivot shaft and the tilt pivot shaft arranged at the upper and lower ends thereof. The second, fourth, and sixth articulated arms A2, A4, and A6 are configured not to accommodate a drive motor. Therefore, the total length of the second, fourth, and sixth joint arms A2, A4, and A6 can be made shorter than when one motor is accommodated therein, and the number of joints is the same, The overall length of the tilting articulated robot can be reduced as compared with the case where the drive motor is arranged on each joint arm.

  Although not shown, one drive motor may be provided for each joint arm. That is, the motor M1 is attached to the joint arm A2 to operate the first joint (horizontal turning shaft 15), the motor M2 is attached to the joint arm A3 to operate the second joint (inclined turning shaft 32), and Similarly, the configuration may be repeated up to the joint arm A7. In this aspect, since the drive motors are held in all the joint arms, the length of each joint arm becomes long, but there is an advantage that the diameter of the arm itself can be reduced and the arm can be made slimmer.

  FIG. 3 illustrates an operation range on the vertical plane of the tilting articulated robot 10 illustrated in FIGS. 1 and 2. When the motor M2 is driven to rotate the second joint (inclined turning shaft 32) by 180 degrees, the tilting articulated robot that has been in the vertical posture becomes the horizontal posture indicated by P1 or P2. When the motor M1 is driven in this posture, the first joint (horizontal turning shaft 15) rotates, and the tilting articulated robot rotates 360 degrees while maintaining the horizontal posture. When the fourth joint (inclined turning shaft 32A) is rotated 180 degrees in the posture of P1 or P2, the portion ahead of the fourth joint that was in the horizontal posture becomes a vertical posture indicated by P3. When the third joint (horizontal turning shaft 15A) is rotated in this state, the portion ahead of the fourth joint moves in the range of 360 degrees within the vertical plane. Further, when the sixth joint (inclined turning shaft 32B) is rotated 180 degrees in the posture shown in P3, the portion ahead of the sixth joint in the vertical posture becomes the horizontal posture shown in P4. When the fifth joint portion (horizontal turning shaft 15B) is rotated in this state, the portion ahead of the sixth joint moves within the range of 360 degrees within the horizontal plane. The curve connecting the tips of the tilting articulated robot in FIG. 3 draws the movement trajectory of the outermost edge, and indicates the maximum operating range of the tilting articulated robot of the form shown in FIG.

  FIG. 4 is a diagram showing an operation range when the tip portion of the tilting articulated robot takes a vertical posture, and description of a specific movement mode of each joint is omitted, but as in the case of FIG. From the curve connecting the tips of the articulated robot, it is possible to grasp the maximum operating range in the above posture in the tilting articulated robot of the form shown in FIGS.

  As described with reference to FIGS. 3 and 4, the above-described tilting articulated robot 10 has a large number of joints and a large degree of freedom of movement in a three-dimensional space, and has a slim configuration as a whole. Therefore, it can be effectively used as an auxiliary robot in the welding system by attaching various tools to its tip. It can also be used as a welding robot itself. Thereby, an improved welding system is constructed which is generalized and simplified.

  FIG. 5 shows an example of a tilting articulated robot 10 when used in the welding system of the present invention. FIG. 5a shows a case where a small part (second work) is transported, positioned and fixed to a large work (first work) set in a welding area when used as an auxiliary robot. A workpiece holding jig 60 is replaceably attached to the tip of the tilting articulated robot 10A, and small parts are attached to the workpiece holding jig 60 by appropriate clamping means or magnetic means. (Second work) 96 is mounted.

  The tilting articulated robot 10B shown in FIG. 5b has a clamp mechanism 70 attached to the tip. In this form of the tilting articulated robot 10B, for example, the welding robot has a plurality of points of the first work and the second work set on the appropriate pedestal in the welding area using positioning pins. When welding, an auxiliary robot that moves following the movement of the welding robot and clamps the first workpiece and the second workpiece near each welding point to ensure the welding operation of the welding robot, etc. As an effective use.

  A tilting articulated robot 10C shown in FIG. 5c has a welding mechanism 80 attached to the tip. In this case, the tilting articulated robot 10C is not used as an auxiliary robot but as a welding robot itself in a welding system.

  FIG. 6 shows an example of a welding system constructed using the above-mentioned tilting articulated robots 10A, 10B, and 10C as auxiliary robots or welding robots themselves. In this example, the welding system has a welding area 91 surrounded by a fence 90 around four sides, and an accessory part (second workpiece) mounting area 92 located outside the welding area 91, and an auxiliary robot is provided in the welding area 91. Two tilting articulated robots 10A (10A1, 10A2) and a tilting articulated robot 10C as a welding robot are arranged. The welding robot may be a conventional polar coordinate articulated robot as shown in FIG.

  A first workpiece 94 is set on an appropriate pedestal 93 in the approximate center of the welding area 91, and the two tilting articulated robots 10 </ b> A are arranged from the mounting area 92 in the welding area 91. Yes. In the area facing the mounting area 92 of the fence 90, an entrance 100 to the welding area 91 is provided, and windows 95A and 95B are provided on both sides corresponding to the tilting articulated robots 10A1 and 10A2. is there. Then, parts tables 97A and 97B for small parts (second workpiece) 96 are placed on the mounting area 92 side of the windows 95A and 95B. In FIG. 6, reference numeral 10D denotes a second auxiliary robot, which is used to change the posture and angle of the first workpiece 94 supported by the pedestal 93. Depending on the welding environment, the pedestal 93 may be removed and the first workpiece 94 may be supported only by the second auxiliary robot 10D.

  In the state shown in FIG. 6, one tilting articulated robot 10A1 is in the process of mounting a small part (second workpiece) 96 in the mounting area 92, and the other tilting articulated robot 10A2 is already mounted. The small component 96 is positioned and fixed at a predetermined position on the first workpiece 94. The welding robot 10 </ b> C moves to the fixed accessory part 96 to perform the required welding. Since the welding process proceeds without the operator P entering the welding area 91, high safety is ensured.

  The merit of the welding system of the present invention will be described based on a more specific aspect. FIG. 7 shows an example in which a tilting articulated robot 10A having a workpiece holding jig 60 attached to the tip is used as an auxiliary robot. The floor portion of an automobile is set as the first workpiece 94 described in FIG. ing. Assume that five small parts (second workpiece) 96 are welded to the set floor portion 94. As described above, two tilting articulated robots 10A1 and 10A2 are used, and a work holding jig 60A having two holding legs is attached to the tip of one tilting articulated robot 10A1, Two small parts 96a and 96b are attached thereto. A workpiece holding jig 60B having three holding legs is attached to the tip of the other tilting articulated robot 10A2, and three small parts 96c, 96d, and 96e are attached thereto.

  First, it is assumed that the small parts 96a and 96b are attached to the tilting articulated robot 10A1, and the small parts 96a and 96b are welded by operating the tilting articulated robot 10A1. As shown in FIG. 8b, the small parts 96a and 96b are placed together on the parts base 97A on the small part mounting area 92 side, and the workpiece is operated by operating the tilting articulated robot 10A1 as shown in FIG. 9b. Since the holding jig 60A can be set at an arbitrary angle, the walking distance of the worker P is small, and the small parts 96a and 96b can be mounted on the work holding jig 60A in a standing posture with the back straight. Become. Thereby, the burden on the worker P is greatly reduced. Further, as described above, it is not necessary for the operator P to enter the welding area 91, and safety is also ensured.

  After mounting the parts, the tilting articulated robot 10A1 is operated to position one small part 96a at a predetermined position of the floor portion 94, and firmly fixed at that position. This fixing can be surely performed by controlling the tilting articulated robot 10A1. In this state, the welding robot 10C is operated to weld the first accessory component 96a to the floor portion 94. The tilting articulated robot 10A1 is operated again, the second small part 96b is positioned at a predetermined position on the floor portion 94, firmly fixed, and welding is performed by the welding robot 10C.

  During the above welding process, the three small parts 96c, 96d, and 96e are mounted on the work holding jig 60B attached to the tip of the other tilting articulated robot 10A2. As in the case of the tilting articulated robot 10A1, the small parts 96c, 96d, and 96e are collectively placed in the small parts mounting area 97B, and the worker P moves from the parts base 97A to the parts base 97B in the small parts mounting area 92. The necessary installation work can be completed only by moving to. The fact that the burden on the operator is small and the safety is ensured is the same as when the small parts 96a and 96b are mounted on the tilting articulated robot 10A1.

  In mounting (setting) the small parts 96c, 96d, 96e on the tilting articulated robot 10A2, another tilting articulated robot 10A1 operates in the welding area 91 in cooperation with the welding robot 10C. One tilting articulated robot 10A1 finishes the cooperative work with the welding robot 10C, and at the same time, the other tilting articulated robot 10A2 is allowed to participate in the welding auxiliary work in the welding area 91. be able to. Therefore, as indicated by a circle Q in the cycle diagram of FIG. 10, the actual operation time of the welding robot 10C can be lengthened, and the welding work efficiency is greatly improved.

  Incidentally, FIG. 8a shows a working mode in a conventional welding system. Conventionally, as shown in FIG. 8a, since the operator has carried the five small parts 96 one by one to a predetermined position of the floor portion 94 set in the welding area 91, the necessary walking is performed. The welding robot could not be operated until the distance was long and all small parts were fixed. In addition, a clamp-dedicated jig (not shown) that can clamp all small parts simultaneously is also required. Further, in consideration of the operability of the welding robot, the floor portion 94 is normally held in a horizontal posture. Therefore, as shown in FIG. The operator had to take a bent posture, which was a heavy burden on the operator. As described above, such inconveniences are all eliminated by the welding system according to the present invention.

  In the above description, the two tilting articulated robots 10A1 and 10A2 are used as auxiliary robots, and different types of work holding jigs 60A and 60B are attached to the tips of the auxiliary robots. There are many other variations of one example of a welding system according to the invention. For example, when the number of small parts (second workpieces) is small, the intended purpose can be sufficiently achieved only by using one tilting articulated robot 10A as an auxiliary robot. In addition, two or more types of workpiece holding jigs (for example, workpiece holding jigs 60A and 60B) of different forms may be selectively attached to the tip of one tilting articulated robot 10A. Many types of small parts can be welded to the floor portion (first workpiece) 94 with one tilting articulated robot 10A. It will be easily understood that the operation time of the welding robot can be extended even in the latter case.

  Still another aspect of the welding system of the present invention is an aspect in which a tilting articulated robot 10B provided with a clamp mechanism 70 shown as 10B in FIG. 5 is used as an auxiliary robot. As shown in FIG. 11, when both the first workpiece 94 and the second workpieces 96 </ b> A and 96 </ b> B are relatively large, the first workpiece 94 is placed on an appropriate pedestal (not shown) in the welding area 91. The workpiece 94 and the second workpieces 96A and 96B are set using positioning pins or the like, and are clamped together by a dedicated clamp jig 76 having a number of clamps 75, and a welding robot welds the vicinity of the clamp points. To be done. Such a clamp-dedicated jig 76 needs to be newly prepared as the shape of the workpiece is changed, and this is a heavy burden at an actual welding site or assembly site.

  In the welding system of the present invention, instead of the conventional clamp-dedicated jig 76, a tilting articulated robot 10B provided with the clamp mechanism 70 at the tip is used. That is, as shown in FIG. 12, the first workpiece 94 and the second workpieces 96A and 96B to be welded use positioning pins or the like on an appropriate base (not shown) in the welding area 91 as in the prior art. It is set. Around it, a tilting articulated robot 10B and a welding robot 10C are arranged, and when welding the point W1, the tilting articulated robot 10B is operated (track 1), and the welding point is clamped by the clamp mechanism 70 at the tip thereof. The vicinity of W1 is clamped (the vicinity of other welding points W2 to W6 is left without being clamped). In this state, the welding robot is operated (track 1) to weld the point W1.

  Next, both the tilting articulated robot 10B and the welding robot 10C are operated (track 2) and moved to the vicinity of the second welding point W2. At that position, the vicinity of the welding point W2 is clamped by the clamp mechanism 70 of the tilting articulated robot 10B, and the point W2 is welded by the welding robot 10C. Thereafter, the same operation is performed for all the welding points. Such a welding mode can also be easily realized because the tilting articulated robot 10 can reduce the dead space while having a wide operation area, and can be configured to be slim as a whole. Even when the shape and size of the first workpiece 94 and the second workpiece 96 to be welded are changed, it can be dealt with only by changing the control program of the tilting articulated robot 10B so as to follow it. It is easy to produce for the vehicle type, and it is not necessary to prepare a clamp-dedicated jig each time, leading to a significant cost reduction.

  Note that the tilting articulated robot shown in FIGS. 1 and 2 for use as an auxiliary robot in the welding system of the present invention is one preferred form and can take many other forms. For example, although the number of joints has been described as six, it may be more or less. What is necessary is just to select suitably according to the request | requirement of a welding field. Moreover, although what showed the horizontal rotation axis | shaft and the inclination rotation axis | shaft alternately was shown, two or more inclination rotation axes can also be arrange | positioned continuously. In this case, it is desirable that the inclination angle of the inclined turning axis is smaller than 45 degrees with respect to the reference vertical axis. Also in the robot shown in FIGS. 1 and 2, the tilt angle of the tilt rotation axis may be an angle other than 45 degrees with respect to the reference vertical axis. The speed reduction mechanism is not limited to the gear speed reduction mechanism, and other speed reduction mechanisms may be used. It can also be used in combination with a gear reduction mechanism.

1 is an overall view showing an embodiment of a tilting articulated robot that is effectively used as an auxiliary robot in the welding system of the present invention. FIG. Sectional drawing which expands and shows a part of tilting articulated robot shown in FIG. The figure explaining the action | operation range of the tilting articulated robot shown in FIG. The other figure explaining the operation | movement range of the tilting articulated robot shown in FIG. FIGS. 5A and 5B are diagrams illustrating a specific aspect of the tilting articulated robot when used in the welding system of the present invention, FIG. 5A is an aspect in which a work holding jig is replaceably attached to the tip, and FIG. FIG. 5c shows a mode in which a welding mechanism is mounted at the tip. Schematic which shows an example of the welding system by this invention. The figure explaining the case where welding is performed using the tilting articulated robot which attached the workpiece holding jig to the front end as an auxiliary robot. FIG. 9 is a diagram illustrating a comparison between a work mode in a conventional welding system (FIG. 8 a) and a work mode in a welding system according to the present invention (FIG. 8 b). The figure which compares and demonstrates the operator's attitude | position (9a) in the conventional welding system, and the operator's attitude | position (FIG. 9b) in the welding system by this invention. The cycle diagram which compares and demonstrates the operation time of the robot in the conventional welding system, and the operation time of the robot in the welding system by this invention. Schematic explaining the other aspect of the conventional welding system. Schematic explaining the other aspect of the welding system by this invention. The figure explaining the conventional industrial robot.

Explanation of symbols

  10, 10A, 10B, 10C, 10D ... tilting articulated robot, A1 to A7 ... joint arm, M ... drive motor, C ... cables, 15, 15A, 15B ... horizontal turning axis (first turning axis), 32, 32A, 32B ... inclined pivot axis (second pivot axis), 60 ... work holding jig, 70 ... clamping mechanism, 80 ... welding mechanism, 90 ... fence, 91 ... welding area, 92 ... second work piece Mounting area, 93 ... pedestal, 94 ... first work (floor member), 95 ... windows, 96a to 96e ... small parts (second work), 96A, 96B ... relatively large second work, 97 ... Parts table, P ... Worker

Claims (8)

A welding system for welding and integrating a first workpiece and a second workpiece held in a predetermined posture using a welding robot,
The welding system is equipped with an auxiliary robot that assists the welding robot in performing the desired welding.
The auxiliary robot has a portion where joint arms are connected to each other via a first turning axis, and a second turning axis having an axis that is inclined to the axis of the first turning axis. It is a tilting articulated robot having a configuration in which at least one connected portion and a motor and a speed reduction mechanism for driving each turning axis are arranged for each turning axis. Features welding system.   A tilting articulated robot as an auxiliary robot is provided with a work holding jig that holds a second work at the tip, and the tilting articulated robot moves the second work to a predetermined position of the first work by the movement. The welding system according to claim 1, wherein the welding robot is configured to assist the welding robot as expected by performing an operation of positioning and fixing at the position.   The workpiece holding jig can hold two or more types of second workpieces. An operation for positioning the second workpiece at a predetermined position of the first workpiece and fixing the second workpiece to the predetermined position is performed for each second workpiece. 3. The welding system according to claim 2, wherein the welding system is adapted to assist the welding robot to perform the intended welding by repeatedly performing it for each workpiece.   Two or more types of work holding jigs are prepared, and a tilting articulated robot as an auxiliary robot can selectively mount different types of work holding jigs at the tip. The welding system according to 2 or 3.   The area where the tilting articulated robot as the auxiliary robot mounts the second workpiece on the workpiece holding jig and the area where the welding robot performs the welding work are separated from each other. A welding system according to crab.   The tilting articulated robot as an auxiliary robot has a clamp at the tip, and the tilting articulated robot moves following the movement of the welding robot, and the first workpiece and the second workpiece near the welding point. 2. The welding system according to claim 1, wherein the tilting articulated robot assists the welding robot to perform the intended welding by performing a step of clamping the first and second joints.   A second auxiliary robot for supporting the first workpiece is provided. The second auxiliary robot also includes a portion where the joint arms are connected to each other via the first rotation axis, and the first rotation. Each having at least one place connected via a second swivel shaft having an inclined axis about the axis of the shaft, and a motor and a speed reduction mechanism for driving each swivel The welding system according to any one of claims 1 to 6, wherein the welding system is a tilting articulated robot having a configuration arranged for each turning axis.   The welding robot is also connected via the second turning axis having the axis center line inclined to the location where the joint arms are connected via the first turning axis and the axis line of the first turning axis. The motor and the speed reduction mechanism for driving each turning axis are each a tilting articulated robot having a configuration arranged for each turning axis. The welding system according to any one of claims 1 to 7.

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