JP2012024801A - Hemming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hemming device which has improved accuracy of hemming work, suppresses the occurrence of trouble and furthermore enables a single hemming device to perform hemming work and welding thereby achieving reduction in equipment cost and the number of man-hour and shortening of a production line.SOLUTION: The hemming device (10) includes: a welding section (60) having a movable electrode (64) for welding a workpiece (W); a support member (3) which freely rotatably supports pressing rollers (2b, 2c) and also supports the movable electrode (64); and a drive device (4) which is mounted to a robot (1) and which rotates the support member (3). A portion of the support member (3), the portion being apart from both portions at which the support member (3) supports the pressing rollers (2b, 2c) and the movable electrode (64) respectively, is fixed to a rotation shaft of the drive device (4). The torque generated by the drive device (4) rotates the support member (3) to press the pressing rollers (2b, 2c) and the movable electrode (64) against the workpiece (W).

Description

  The present invention relates to a hemming device that performs processing while pressing a pressure roller against a workpiece.

  FIG. 11 is an overall view of a conventional roller type hemming device. As shown in FIG. 11, the conventional roller type hemming device 70 includes a multi-axis controllable robot hand 72 that has been taught in advance so as to perform a predetermined movement, and a pressure attached to the tip of the robot hand 72. It has a roller support portion 73 and a pressure roller 74 that is supported by the pressure roller support portion 73 so as to be displaceable and pressed against the workpiece W. The workpiece W is, for example, a vehicle door configured by an outer panel Wo and an inner panel Wi.

  FIG. 12A is a longitudinal sectional view showing a conventional example 1 of the pressure roller support portion 73. A support bracket 41 is fixed to the distal end portion of the robot hand 72 with bolts 12. In the support bracket 41, a slide hole 41c and a spring hole 41b are concentrically formed in a block body having a predetermined shape. The slide hole 41c is a square hole having a square cross section.

  A spring 10a is inserted into the spring hole 41b. The spring 10a presses the slide block 13 downward. The slide block 13 can be displaced in the center line Y direction within the slide hole 41c.

  The pressure roller 74 is attached to the slide block 13. The center line X of the rotation shaft of the pressure roller 74 and the center line Y extending in the displacement direction of the slide block 13 are substantially orthogonal. The pressure roller 74 is arranged with its outer peripheral surface offset in the radial direction with respect to the center line Y extending in the displacement direction of the slide block 13.

  FIG. 12B is a longitudinal sectional view showing Conventional Example 2 of the pressure roller support portion 73. The pressure roller support portion 73 of the conventional example 2 is a servo motor system.

  A servo motor 50 having a rotary encoder 52 is attached to the upper surface of the support bracket 51. A screw shaft 54 a of a ball screw mechanism is connected to the output shaft 50 a of the servo motor 50 through a coupling 53. A slide hole 55a is formed in the slide block 55 from the upper surface to the lower surface. A nut 54b is fitted in the sliding hole 55a so as to be slidable in the axial direction. The nut 54 b is prevented from rotating with respect to the slide block 55 by a key 57.

  In this way, the nut 54b can slide in the sliding hole 55a. The slidable range is a range in which the flange 54c of the nut 54b can be displaced between the bottom surface of the sliding hole 55a and the retainer 56. Further, a load cell 58 for load measurement is attached between the lower end of the nut 54b and the bottom surface of the sliding hole 55a.

  The encoder 52 and the load cell 58 are connected to an external control device such as a sequencer through a servo amplifier. The servo motor 50 is connected to a motor driver, and this motor driver is also connected to an external control device.

  When the pressure roller 74 is pressed by the bent portion of the workpiece W and hemming is performed, if the robot hand 72 bends, the pressing force of the pressure roller 74 becomes insufficient. In order to avoid this, the position of the pressure roller 74 is corrected by rotating the servo motor 50 until the load detected by the load cell 58 reaches a predetermined value. Thereby, an appropriate pressing force by the pressure roller 74 is always secured.

  Also, in the case of the conventional example 2, as in the case of the conventional example 1, the center line X of the rotating shaft of the pressure roller 74 and the center line Y extending in the displacement direction of the slide block 55 are substantially orthogonal, The pressure roller 74 is disposed offset in the radial direction with respect to the center line Y extending in the displacement direction of the slide block 55.

Japanese Patent No. 2669282 (paragraphs 0014 to 0028, FIGS. 2 and 12)

  Incidentally, in the conventional example 1 as shown in FIG. 12A, the pressure roller 74 is displaced along the inner peripheral surface of the slide hole 41c of the support bracket 41. If the processing accuracy of the slide hole 41c is low, highly accurate hemming processing becomes difficult. However, since the slide hole 41c is a square hole having a square cross section, a special finishing process is required to increase the processing accuracy of the inner surface, and there is a problem of cost.

  Further, in Conventional Example 2 shown in FIG. 12B, a load cell 58 is attached to the lower part of the ball screw 54, and an electric wire connected to the load cell 58 is routed. There is a possibility that a trouble that the electric wire interferes with an edge of the workpiece W and is cut during machining of the workpiece W may occur.

  Furthermore, in the conventional examples 1 and 2, the pressure roller 74 is offset in the radial direction with respect to the center line Y extending in the displacement direction of the slide blocks 13 and 55. For this reason, if a reaction force acts on the pressure roller 74 from the workpiece W during processing, the reaction force is applied to the slide blocks 13 and 55 as an offset load, and the slide blocks 13 and 55 are moved with respect to the center line Y. It will act in the direction of tilting. When the slide blocks 13 and 55 are subjected to such a reaction force, sliding resistance is generated by rubbing against the sliding surface, and smooth movement is hindered. As a result, the pressure roller 74 can follow the workpiece W. There was a problem of getting worse.

  In addition to the hemming process, the workpiece W may be welded. In this case, since the conventional hemming apparatus can only perform hemming, another welding apparatus must be provided, the equipment cost increases, the production line is difficult to shorten, and the cost of the product increases. It was.

  The present invention has been made in view of the above problems, and its object is to improve the accuracy of the hemming process, suppress the occurrence of troubles, and further perform the hemming process and welding in a single way. The purpose of this is to reduce the equipment cost, reduce the number of man-hours, and shorten the production line.

  In order to solve the above problems, in the present invention, a pressure roller and a movable electrode for welding are attached to a support member that is rotated by a driving device, and the pressure roller and the movable electrode are supported by the torque of the driving device. To press against the workpiece.

  The first invention is configured to hemming the workpiece (W) while pressing the pressure rollers (2b, 2c) attached to the robot (1) against the workpiece (W) placed on the anvil (8). The hemming device (10) is configured to rotatably support a welding portion (60) having a movable electrode (64) for welding the workpiece (W) and the pressure rollers (2b, 2c), and A support member (3) for supporting the movable electrode (64); and a drive device (4) attached to the robot (1) for rotating the support member (3). The parts of the pressure roller (2b, 2c) and the movable electrode (64) that are separated from the support parts are fixed to the rotating shaft of the drive unit (4), and the support is provided by the torque generated by the drive unit (4). The member (3) is rotated to Roller (2b, 2c) and the movable electrode (64) is characterized in that it is configured to press on the workpiece (W).

  According to this structure, hemming and welding can be performed with a single device by providing the welded portion. This eliminates the need for a welding device separate from the hemming device, thereby reducing the equipment cost and shortening the production line. In addition, since the workpiece after hemming can be welded on this apparatus without transporting it to another welding apparatus, the number of man-hours is reduced.

  Further, during hemming or welding, the pressure roller and the movable electrode are pressed against the workpiece by the torque of the driving device. This eliminates the need for a structure for moving the slide block within the slide hole as in the conventional example, and thus eliminates the need for special high-precision finishing.

  Further, since the pressure roller and the movable electrode are pressed against the work by torque, it is possible to obtain an appropriate pressing force without using a load cell as in the conventional example 2. As a result, it is not necessary to route a load cell wire around the pressure roller and the movable electrode, and troubles can be prevented.

  Furthermore, since the pressure roller and the movable electrode can be moved by the rotation of the support member, there is no problem of sliding resistance due to rubbing due to the unbalanced load as in the conventional example, and the followability to the workpiece Is good.

  According to a second aspect, in the first aspect, the weld portion (60) includes a ground wire (65) connected to the anvil (8), and is configured to perform indirect spot welding. It is characterized by.

  According to this configuration, the workpiece can be welded by moving only the spot welding movable electrode by the robot.

  According to a third aspect, in the second aspect, the movable electrode (64) is disposed away from the pressure roller (2b, 2c) in the rotation direction of the support member (3). It is what.

  According to this configuration, it is possible to change the positions of the pressure roller and the movable electrode and to use both by simply rotating the support member.

  According to a fourth invention, in any one of the first to third inventions, the driving device (4) includes a servo motor (4a), and the servo motor (4a) includes the pressure roller (2b, 2c) and indexing control for indexing the movable electrode (64) to a usable position.

  According to this configuration, the pressure roller and the movable electrode can be easily and reliably switched and used by indexing control. In addition, since the torque can be easily increased or decreased by using the servo motor, it is possible to generate a pressing force suitable for each of the pressure roller and the movable electrode by simple control.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the support member (3) includes a plurality of pressure rollers (2b, 2c) on a rotation center line of the support member (3). It is characterized by being arranged at intervals in the circumferential direction.

  According to this configuration, for example, by disposing different types of pressure rollers on the support member, the type of the pressure roller can be switched and the pressure roller and the movable electrode can be switched simply by rotating the support member. Can be easily switched.

  According to the first invention, since the welding portion is provided, hemming and welding can be performed by a single device, thereby reducing the equipment cost, reducing the man-hours, and shortening the production line. This can reduce the cost of the product. In addition, the pressure roller and movable electrode are pressed against the workpiece by the torque of the drive unit, so that a particularly high-precision finishing process is not required and the cost can be further reduced. This makes it possible to perform high-quality hemming with good followability. Furthermore, a load cell is not necessary, and trouble can be prevented.

  According to the second aspect of the invention, since indirect spot welding is performed, only the movable electrode needs to be moved by the robot in the welded portion, and the size can be reduced. Thereby, size reduction of the hemming apparatus provided with the welding part can be achieved.

  According to the third aspect, the pressure roller and the movable electrode can be switched quickly and used by rotating the support member.

  According to the fourth invention, the pressure roller and the movable electrode are indexed and controlled by the servo motor, so that the pressure roller and the movable electrode can be switched reliably with a simple structure and added. A pressing force suitable for each of the pressure roller and the movable electrode can be easily obtained, and the quality of the product can be improved.

  According to the fifth invention, since the plurality of pressure rollers are arranged at intervals in the circumferential direction of the rotation center line of the support member, both the switching of the type of the pressure roller and the switching of the movable electrode are performed. Can be done easily. Accordingly, welding can be performed while speedily performing hemming using a hemming device having a plurality of types of pressure rollers, and the number of man-hours can be reduced.

It is a perspective view showing the whole hemming device concerning the embodiment of the present invention. It is a side view of a roller head. It is sectional drawing of a roller head. It is a perspective view of a roller head. (A) is a side view which shows the final bending process state by the pressure roller for final bending, (b) is sectional drawing which shows the same processing state. It is a perspective view of an intermittent mechanism. FIG. 6 is a view corresponding to FIG. The preliminary | backup bending apparatus of the corner part of an anvil is shown, (a) is the fragmentary sectional view seen from the side surface, (b) is the C arrow enlarged view shown to (a). It is a 3rd page figure of a pre-bending punch, (a) is a top view, (b) is a left view, (c) is a front view. It is a perspective view which shows the bending part of the workpiece | work after a preliminary | backup bending process. It is a general view of the conventional hemming device. The structure of the conventional roller support part is shown, (a) is sectional drawing of a spring system, (b) is sectional drawing of a servo motor system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  FIG. 1 shows a hemming device 10 according to an embodiment of the present invention. Examples of the workpiece W to be hemmed using the hemming device 10 include lids such as automobile doors, bonnet hoods, and trunk lids. However, the workpiece W is not particularly limited as long as it is a combination of panel materials.

  The hemming device 10 includes a robot 1, a roller head 6 attached to the tip of a robot hand 1 a included in the robot 1, an anvil 8 for placing a workpiece W, and an indirect welding device (welding portion) 60. And hemming and welding can be performed with a single device.

  As shown in FIG. 1, in this embodiment, the robot 1 is a multi-joint general-purpose robot in which a total of six axes including three basic axes and three wrist axes are controlled. The robot 1 is provided at a base 1f fixed to the ground, a lower arm 1d provided so as to be able to turn on the base 1f, an upper arm 1c connected to a distal end portion of the lower arm 1d, and a distal end portion of the upper arm 1c. A robot hand 1a and a balancer 1e. A bendable joint 1b is provided at the tip of the upper arm 1c. A robot hand 1a is attached to the upper arm 1c via the joint 1b.

  The three basic axes of the robot 1 are an axis that serves as a turning center when the main body of the robot 1 is turned on the base 1f (the turning direction is indicated by an arrow S), and an axis that serves as the turning center of the lower arm 1d (turns). The movement direction is indicated by an arrow L), and the axis is the axis of rotation of the upper arm 1c (the rotation direction is indicated by an arrow U).

  By controlling these three basic axes, the position of the robot hand 1a in the space is determined.

  Further, the wrist 3 axis is an axis serving as a turning center for turning the robot hand 1a with respect to the upper arm 1c (a turning direction is indicated by an arrow R), and an axis serving as a turning center for swinging the robot hand 1a (the swinging direction is determined). And an axis that is the center of rotation of the robot hand 1a (the direction of rotation is indicated by an arrow T).

  The robot 1 is preferably, for example, MOTOMAN (registered trademark) ES165N, but is not limited thereto.

  As shown in FIG. 1, the anvil 8 is disposed in the vicinity of the robot 1. The anvil 8 serves as an anvil during hemming. The anvil 8 includes a frame 8a having a curved surface that matches the shape of the workpiece W, and the workpiece W is placed on the frame 8a.

  When the work W is, for example, a vehicle door, the frame 8a of the anvil 8 is configured to have a curved surface that matches the outer shape of the door outer panel Wo (shown in FIG. 5). The lateral width of the anvil 8 is set in accordance with the shape of the workpiece W. When the workpiece W is a vehicle door, for example, it is about 1.1 m. In addition, the anvil 8 can be replaced when changing the lot number or performing maintenance.

  In addition, as shown in FIG.5 (b), the workpiece | work W is equipped with the inner panel Wi other than the outer panel Wo. The inner panel Wi is disposed on the surface of the outer panel Wo on the vehicle interior side. The outer panel Wo and the inner panel Wi are joined by bending a bent portion provided on the outer peripheral portion of the outer panel Wo so as to sandwich the peripheral portion of the inner panel Wi. Hemming is a process in which a bent part of the outer peripheral part of the outer panel Wo is bent to sandwich the peripheral part of the inner panel Wi. Although this hemming process will be described in detail later, it is divided into a pre-bending process and a main-bending process, and the pre-bending process is a state before the bent part rising from the peripheral part of the outer panel Wo becomes the final shape. The main bending process is a process for making the bent part into a final shape after the preliminary bending process.

  The frame 8a of the anvil 8 has a substantially quadrilateral shape in plan view so as to match the outer shape of the workpiece W. As shown in FIG. 1, pre-bending devices 9 for pre-bending the workpiece W are provided at four corners of the frame 8a.

  Each preliminary bending device 9 includes a preliminary bending punch 9d and an air actuator 9a that operates the preliminary bending punch 9d.

  In addition, one or two clampers 7 a to 7 h for fixing the work W to the anvil 8 are arranged on each side of the frame 8 a of the anvil 8. These clampers 7a to 7h are also provided with an air actuator for operation.

  As shown in FIG. 2, the roller head 6 rotatably supports the pressure rollers 2 b and 2 c, supports the movable electrode 64 of the welding portion 60, and a drive device that rotates the support member 3. 4 (see FIG. 3) and a support head 5 for fixing the driving device 4 to the robot 1. The roller head 6 is connected as a unit to the connecting portion of the robot hand 1a.

  The support head 5 includes a disk-like flange portion 5b fastened to a flange provided at the tip of the robot hand 1a, and a drive device attachment portion 5a that protrudes in a direction orthogonal to the flange portion 5b and extends in a plate shape. As a whole, as shown in FIG. 3, the member is formed in a T-shaped cross section.

  The flange portion 5b of the support head 5 is configured along the flange of the robot hand 1a. A convex shape is provided at the center of the flange portion 5 b of the support head 5. By inserting this convex shape into a hole formed in the connecting portion of the robot hand 1a, the support head 5 is centered. The support head 5 is fastened to the flange of the robot hand 1a by a plurality of bolts.

  As shown in FIG. 3, the drive device mounting portion 5a of the support head 5 is formed with a through hole 5c that penetrates in the thickness direction. The drive device 4 is inserted into the through hole 5c. The drive device 4 is provided with a mounting flange 4b. A plurality of insertion holes through which the bolts are inserted are formed in the mounting flange 4b, and the driving device 4 is fastened to the support head 5 by the bolts inserted through these insertion holes.

  The drive device 4 includes a servo motor 4a and is controlled by a control device (not shown). This servo motor 4a has a built-in speed reducer with a reduction ratio of 1/90. The output of the servo motor 4a is transmitted to the output shaft (rotating shaft) 4c through the speed reducer.

The rated rotation speed of the servo motor 4a is 3.37 min- ¹ .

  The servo motor 4a incorporates a rotary encoder and an electromagnetic brake (not shown). This rotary encoder converts the rotation amount of the servo motor 4a into an electric signal. By processing the electrical signal output from the rotary encoder, it is possible to detect the rotation angle (position), the rotation speed, and the like. The electromagnetic brake is for holding the stop position of the drive device 4.

  The servo motor 4a is subjected to three controls including torque control, speed control, and position control.

  The torque control is control for changing the torque generated by the servo motor 4a by controlling the current flowing through the servo motor 4a. In other words, the generated torque of the servo motor 4a can be controlled to be an arbitrary torque according to the torque command signal. In the torque control mode, the servo motor 4a can be rotated with a constant torque regardless of the rotation speed.

  The speed control is a control that changes the rotation speed of the servo motor 4a steplessly. That is, the rotational speed of the servo motor 4a can be controlled in accordance with the speed command signal. In the speed control mode, the servo motor 4a can be rotated at a constant rotation speed regardless of the load.

  In the position control, the rotation angle (position) and rotation speed of the servo motor 4a are controlled. In the position control, the servo motor 4a is moved so as to have the commanded rotation angle, and is held at the rotation angle.

  As shown in FIG. 1, the indirect welding device 60 includes a welding control device 61, a ground wire 62, a movable electrode 64 (shown in FIG. 2), a connection line 65 connected to the movable electrode 64, and a connection line. And an interrupting mechanism 66 for interrupting the middle part of 65. The ground wire 62 is connected to the frame 8 a of the anvil 8.

  As shown in FIGS. 2 and 3, the support member 3 is made of a plate material, and a shaft insertion hole 3 a into which the output shaft 4 c of the drive device 4 is fitted is formed at the center. As shown in FIG. 2, the support member 3 includes first to third arm portions 3b, 3c, and 3d that extend radially from the shaft insertion hole 3a in the radial direction. The first to third arm portions 3b, 3c, 3d are formed at equal intervals every 120 °. The support member 3 rotates integrally with the output shaft 4c.

  The supporting member 3 supports the main bending pressure roller 2b, the small step pressure roller 2c, and the movable electrode 64.

  The movable electrode 64 supported by the support member 3 is attached to the first arm portion 3 b of the support member 3. The movable electrode 64 is formed in a rod shape. An electrode holder 67 is provided on the distal end side of the first arm portion 3 b of the support member 3. The electrode holder 67 holds the movable electrode 64 so that the movable electrode 64 protrudes in the tangential direction of the output shaft 4 c of the drive device 4.

  The electrode holder 67 is provided with a connector portion 68 for connecting the connection line 65. The connection line 65 is electrically connected to the movable electrode 64 via the connector portion 68 and the electrode holder 67.

  The movable electrode 64 can be moved around the output shaft 4 c by rotating the support member 3 by the driving device 4. 4 shows a state where the movable electrode 64 is in the usable position, and FIG. 2 shows a state where the movable electrode 64 is in the non-use position. At a position where the movable electrode 64 is not used, the main bending pressure roller 2b or the small step pressure roller 2c can be used.

  The pressing force that presses the movable electrode 64 against the workpiece W is obtained by the torque of the driving device 4. That is, the movable electrode 64 is moved to the usable position shown in FIG. 4, and the robot 1 is moved to the welding portion of the workpiece W so that the tip of the movable electrode 64 is applied to the workpiece W. At this time, the movable electrode 64 is pressed against the workpiece W by rotating the support member 3 in the direction in which the movable electrode 64 is pressed against the workpiece W by the torque of the driving device 4. The pressing force of the movable electrode 64 can be adjusted by torque control of the servo motor 4a.

  On the other hand, as shown in FIG. 6, the interrupting mechanism 66 contacts and separates the conductor plate 80, the metal rod 81, and the metal rod 81 that are attached to a portion that pivots around the vertical axis of the robot 1. And an actuator 82 that moves in the direction.

  The conductive plate 80 is formed of a member that conducts electricity, and is formed in an arc shape extending in the turning direction at a portion where the robot 1 turns, and moves in a horizontal direction together with the portion where the robot 1 turns. ing. A connection line 65 (see FIGS. 1, 2, and 4) extending from the movable electrode 64 is connected to the conductor plate 80.

  The actuator 82 is attached to a support 84 fixed to the ground, and is disposed below the conductor plate 80. The operation direction of the actuator 82 is a vertical direction as shown by an arrow in FIG.

  The metal rod 81 conducts electricity and is supported by the actuator 82 so as to extend in the vertical direction below the conductor plate 80. The upper end portion of the metal bar 81 is opposed to the lower surface of the conductor plate 80. A connection line 65 extending from the welding control device 61 is connected to the metal rod 81.

  When the metal rod 81 is driven to the rising end by the actuator 82, the upper end portion of the metal rod 81 comes into contact with the lower surface of the conductor plate 80 and becomes conductive. On the other hand, when the metal rod 81 is driven to the lower end by the actuator 82, It is away from the lower surface and becomes non-conductive.

  Further, as shown in FIG. 2, a main bending pressure roller 2 b is rotatably attached to the second arm portion 3 c of the support member 3.

  The bending pressure roller 2b is a roller for pressing the workpiece W while rolling and performing hemming. The outer peripheral surface (the contact surface with the workpiece W) of the bending pressure roller 2b is subjected to heat treatment for improving wear resistance.

  As shown in FIG. 2, a through hole 2m is provided at the center of the pressure roller 2b for bending. A bearing 2e is mounted inside the through hole 2m. The bearing 2e is held by a snap ring 2f so as not to come out of the through hole 2m.

  A shaft 2d is inserted through the hole in the inner ring of the bearing 2e. A large-diameter head is formed at the end of the shaft 2d, and this head engages with the peripheral edge of the hole in the inner ring of the bearing 2e from the outside.

  The shaft 2d protrudes from the surface on the support member 3 side of the main bending pressure roller 2b. A portion of the shaft 2 d protruding from the main bending pressure roller 2 b is inserted into the mounting hole 3 g of the support member 3. A nut 2n is screwed into the end of the shaft 2d. The main bending pressure roller 2b is attached to the support member 3 by the nut 2n. Accordingly, the main bending pressure roller 2b is supported by the support member 3 so as to be rotatable around the center line of the shaft 2d.

  The bending pressure roller 2b can be replaced. At the time of replacement, a hexagon wrench (not shown) may be inserted into a hexagon hole (not shown) provided in the head of the shaft 2d, and the nut may be loosened with a nut turning tool (not shown).

  As shown in FIGS. 2, 4 and 7, a small step pressure roller 2c is rotatable at the tip of the third arm portion 3d of the support member 3 in the same manner as the main bending pressure roller 2b. It is supported. Accordingly, the bending pressure roller 2b, the small step pressure roller 2c, and the movable electrode 64 are arranged at intervals in the circumferential direction of the output shaft 4c of the drive device 4.

  The small step pressure roller 2c is for hemming a small step portion such as a door character line. The small step pressure roller 2c is a roller having a smaller diameter than the main bending pressure roller 2b.

  The bending pressure roller 2b, the small-step pressure roller 2c, and the movable electrode 64 can be switched to usable positions by changing the position by the rotation of the support member 3.

  Specifically, the driving device 4 is configured to perform indexing control for indexing the main bending pressure roller 2b, the small step pressure roller 2c, and the movable electrode 64 to usable positions. This indexing control is performed by a control device (not shown) that controls the driving device 4. The indexing control means that during the hemming process, the servo motor 4a is rotated so that the used pressure roller 2b and the small step pressure roller 2c are at the usable position, and at the time of welding, In this control, the servo motor 4a is rotated so that the movable electrode 64 comes to the usable position.

  Next, the pre-bending device 9 provided at the corner portion of the anvil 8 will be described with reference to FIG.

  As shown in FIG. 8A, a stay 8b is fixed to the lower surface of the frame 8a of the anvil 8 with bolts. An L-shaped plate 8c is fixed to the lower surface of the stay 8b by bolts.

  A support 9f bent in a dogleg shape is fixed to the side surface of the L-shaped plate 8c. A pin P1 is provided at the lower end of the support 9f. A pin P3 is provided at a bent portion of the support 9f.

  A tumbler 9g is attached to the support 9f. The tumbler 9g is formed in an L shape. A pin P3 passes through an intermediate portion of the tumbler 9g, and the pin 9 is rotatably held with respect to the support 9f by the pin P3. A pre-bending punch 9d is fixed to the upper end of the tumbler 9g with a bolt.

  The preliminary bending apparatus 9 includes an actuator 9a. The actuator 9a has a rod-side trunnion type having a rod 9c. The cylinder portion is rotatably held at the lower end portion of the support 9f by the pin P1.

  Further, the end portion of the rod 9c has a double clevis shape, and the end portion of the tumbler 9g described above is rotatably connected by a pin P2.

  As a result, when high pressure air is supplied to one of the cylinder portions of the actuator 9a and the rod 9c contracts, the actuator 9a rotates to the right position as indicated by the two-dot chain line with the pin P1 as a fulcrum. Further, the tumbler 9g rotates with the pin P3 as a fulcrum, and the preliminary bending punch 9d moves to a standby position away from the workpiece W.

  On the other hand, when high pressure air is supplied to the other of the cylinder parts and the rod 9c protrudes, the preliminary bending punch 9d quickly moves to the position shown by the solid line and becomes the preliminary bending position.

  FIG. 9 is a three-side view of the pre-bending punch 9d, where (a) is a plan view, (b) is a left side view, and (c) is a front view. As shown in FIGS. 9B and 9C, the lower surface of the tip end portion of the pre-bending punch 9d is notched, and a wave shape is formed on the work W in the notched portion. A plurality of projections 9e are provided, thereby forming a corrugated molding surface.

  Next, operation | movement of the hemming apparatus 10 of embodiment comprised as mentioned above is demonstrated.

  First, teaching of the robot 1 is performed. Teaching of the robot 1 refers to a method of creating a program by remote control operation.

  An industrial robot represented by an articulated robot such as the robot 1 operates according to a program in the same manner as an NC machine tool. Therefore, it is necessary to create a program in the same manner as an NC machine tool in order to operate an articulated robot. However, since the articulated robot has six control axes and the creation of the program is complicated and difficult, the pressure rollers 2b and 2c attached to the robot hand 1a of the articulated robot 1 are attached to the anvil 8. A method is employed in which the aircraft is operated with a remote control while being pressed against the top surface, and the posture is stored. That is, a program is created by tracing a predetermined locus with the pressure rollers 2b and 2c and storing the operation.

  It is assumed that the teaching work of the robot 1 has been completed, and the subsequent operation will be described.

  When a start button (not shown) is pressed, the operation of the hemming device 10 starts. The robot hand 1a of the robot 1 has moved to a rear standby position (not shown). An adjacent workpiece transfer robot (not shown) places the outer panel Wo on the upper surface of the anvil 8. Subsequently, the same workpiece transfer robot places the inner panel Wi on the outer panel Wo.

  Thereafter, the work-fixing clampers 7 a to 7 h are simultaneously operated to fix the work W to the upper surface of the anvil 8. Thereby, the setting of the workpiece W is completed.

  After setting the workpiece W, hemming is performed first. Since the indirect welding apparatus 60 is not used during the hemming process, the metal rod 81 of the intermittent mechanism 66 is lowered to be in a non-conductive state.

  In the hemming process, first, the pre-bending punches 9d, 9d... At the four corners of the anvil 8 are actuated simultaneously. As shown in FIGS. 9B and 9C, the molding surfaces of the preliminary bending punches 9d, 9d... Are formed with projections 9e. Is formed into a wave shape and falls and deforms. This is shown in FIG. When the preliminary bending is completed, the preliminary bending punches 9d, 9d... Are switched to the retracted position.

  In addition, although it does not show in figure about preliminary | backup bending of parts other than the corner part of the workpiece | work W, it is possible to perform using another preliminary | backup bending punch and an actuator.

  After the preliminary bending, the main bending process using the robot 1 is performed. The robot 1 moves the bending pressure roller 2b as taught. At this time, the driving device 4 applies a rotational force to the support member 3 so that the main bending pressure roller 2b is pressed against the workpiece W, and the pressing force applied to the workpiece W by the main bending pressure roller 2b is a predetermined force. The generated torque of the drive device 4 is adjusted so that This is performed by torque control of the servo motor 4a. As a result, the main bending pressure roller 2b is pressed against the workpiece W, and the bent portion of the outer panel Wo is pressed by the main bending roller 2b as shown in FIG.

  During the main bending process, the main bending pressure roller 2b approaches the clampers 11a, 11b, 11c,. The clampers 11a, 11b, 11c,... Are switched to a non-fixed position when the main bending pressure roller 2b approaches, so that interference with the main bending pressure roller 2b is avoided. When the bending pressure roller 2b moves away, the clampers 11a, 11b, 11c,... Return to the fixed position.

  At the time of the final bending process, the main bending pressure roller 2b is pressed against the workpiece W by the torque of the driving device 4, so that the structure for moving the slide block within the slide hole as in the conventional example is not required, and the hemming device 10 is provided. This eliminates the need for special high-precision finishing.

  Further, since the main bending pressure roller 2b is pressed against the workpiece W by the torque of the driving device 4, an appropriate pressing force can be obtained by controlling the torque of the servo motor 4a without using a load cell as in the conventional example 2. It becomes possible. Thereby, it is not necessary to route the load cell electric wire around the main bending pressure roller 2b, and troubles can be prevented.

  Further, the main bending pressure roller 2b can be moved by the rotation of the support member 3, so that there is no problem of sliding resistance due to rubbing caused by an unbalanced load as in the conventional example, and the pressure roller The followability to the workpiece W of 2 is good.

  Further, when the work W has a small step portion, the support member 3 is rotated by the indexing control of the driving device 4 so that the small step pressure roller 2c comes to the processing position.

  Thereafter, the pressure roller 2c for small steps is moved by the robot 1. Thereby, the part which comprises the small level | step difference of the workpiece | work W is pressed by the small level | step difference pressure roller 2c, and it becomes a final shape.

  When the hemming process is completed as described above, a welding process is performed. First, as shown in FIG. 4, the support member 3 is rotated by the driving device 4 to bring the movable electrode 64 to the usable position. Then, the movable electrode 64 is applied to the welded part of the workpiece W by the robot 1, and the movable electrode 64 is pressed against the welded part by the torque of the driving device 4. The torque at this time may be lower than the torque during hemming.

  When the turning operation of the robot 1 is completed, as shown in FIG. 6, the metal rod 81 is driven to the ascending end by the actuator 82 and is brought into conduction with the conductor plate 80. Thereafter, current is supplied from the control device 61 to perform indirect spot welding.

  When spot welding at one place is completed, the metal rod 81 is driven to the descending end by the actuator 82 to make it non-conductive. Next, the robot 1 is turned to move the movable electrode 64 to the next welding site. Then, spot welding is performed as described above.

  The movable electrode 64 can be reliably pressed against the workpiece W by the torque of the driving device 4. At this time, an offset load as in the case of the conventional slide structure does not occur, and the movable electrode 64 can be pressed against the workpiece W with a set load and reliably welded.

  As described above, according to the hemming device 10 according to this embodiment, the pressing roller 2 is pressed against the work W by the torque of the driving device 4, so that a particularly highly accurate finishing process is not necessary. Thus, the cost can be reduced, and the followability of the pressure roller 2 to the workpiece W can be improved, and high-quality hemming can be performed. Furthermore, a load cell is not necessary, and trouble can be prevented.

  In addition, the hemming process and the welding process can be performed by the single device 10 while the workpiece W is fixed to the anvil 8. This eliminates the need for a separate welding-dedicated jig, reduces the number of man-hours, and further shortens the production line. Thereby, the cost of a product can be reduced.

  Also, the workpiece W can be welded by moving only the movable electrode 64 by the robot 1. Thereby, size reduction of the hemming apparatus 10 provided with the welding apparatus 60 can be achieved.

  Further, the movable electrode 64 can be reliably pressed against the workpiece W by the torque of the driving device 4. At this time, an offset load as in the case of the conventional slide structure does not occur, and the movable electrode 64 can be pressed against the workpiece W with a set load and reliably welded.

  In addition, the movable electrode 64 is disposed away from the pressure roller 2 in the rotation direction of the support member 3. Thereby, the movable electrode 64 and the pressure roller 2 can be switched and used simply by rotating the support member 3. Further, the switching between the movable electrode 64 and the pressure roller 2 can be performed quickly using the driving device 4.

  Further, the main bending pressure roller 2b, the small step pressure roller 2c, and the movable electrode 64 can be switched and used simply by rotating the support member 3. Thereby, the switching between the main bending pressure roller 2b, the small step pressure roller 2c, and the movable electrode 64 can be performed speedily using the driving device 4. At this time, since the control is performed by the indexing control of the servo motor 4a, the switching can be surely performed with a simple structure.

  In the above embodiment, the two pressure rollers 2b and 2c are attached to the support member 3. However, the present invention is not limited to this, and there may be one pressure roller or three or more pressure rollers. Good. The type of pressure roller may be a pre-bending pressure roller.

  As described above, the hemming device according to the present invention can be used, for example, when processing a vehicle door.

1 Robot 2b Main Bending Pressure Roller 2c Small Step Pressure Roller 4 Drive Device 4a Servo Motor 4c Output Shaft (Rotating Shaft)
8 Anvil 10 Hemming device 60 Indirect welding device (welded part)
62 Ground wire 64 Movable electrode W Work Wi Inner panel Wo Outer panel

Claims (5)

A hemming device (10) configured to hemm the workpiece (W) while pressing the pressure rollers (2b, 2c) attached to the robot (1) against the workpiece (W) placed on the anvil (8). ) And
A weld (60) having a movable electrode (64) for welding the workpiece (W);
A support member (3) for rotatably supporting the pressure roller (2b, 2c) and supporting the movable electrode (64);
A drive device (4) attached to the robot (1) and rotating the support member (3);
A part of the support member (3) away from the support parts of the pressure rollers (2b, 2c) and the movable electrode (64) is fixed to the rotating shaft of the drive device (4),
The support member (3) is rotated by the torque generated by the drive device (4), and the pressure rollers (2b, 2c) and the movable electrode (64) are pressed against the work (W). Hemming device (10) characterized in that Hemming device (10) according to claim 1,
The hemming device (10), wherein the weld (60) includes a ground wire (65) connected to the anvil (8) and is configured to perform indirect spot welding. Hemming device (10) according to claim 2,
The hemming device (10), wherein the movable electrode (64) is disposed away from the pressure rollers (2b, 2c) in the rotation direction of the support member (3). The hemming device (10) according to any one of claims 1 to 3,
The drive device (4) includes a servo motor (4a),
The hemming device (10), wherein the servo motor (4a) performs indexing control for indexing the pressure rollers (2b, 2c) and the movable electrode (64) to usable positions. The hemming device (10) according to any one of claims 1 to 4,
The support member (3) is provided with a plurality of pressure rollers (2b, 2c) spaced apart from each other in the circumferential direction of the rotation center line of the support member (3). Hemming device (10).

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